But before we look at the world, I think it shall be necessary to begin with Antiope's place within it so that we may understand her vantage point.  I do various playthroughs, and in some of them, Antiope is herself the mistress in charge of her own household and the sole owner of the slaves in her care.  This is mostly for the sake of simplicity, however, when the playthrough is orientated toward non-RP motives like testing mods.  Most of the time, Antiope is fully the property of another mistress.  But she is a loyal and trusted pet, and has worked her way to the top of Mistress's illustrious household.  As such, Antiope is ever-present at Mistress's side on her travels and in battle, and many of Mistress's most important jobs are delegated to her.  This includes procuring and training new additions to the household.  

Antiope's Tamriel is a harsh place.  Resources are scarce, and danger is ever-present.  Sadly, the needs of mere survival leave no room for societal luxuries like restorative or rehabilitative justice or the humane treatment of prisoners of war.  For crimes too severe to be recompensed by a fine, corporal and capital punishment are the only viable options—society cannot bear the cost of programmes like long-term incarceration or supervised parole—so serious or serial offenders and enemy combatants would be able to expect no better fate than a short drop and a sudden stop.  Unless...

Tamriel society is highly stratified by social class, with an entrenched nobility at the top; merchants, artisans, military officers, and the landed gentry in the middle; and manual labourers, sellswords, and landless vagrants below them.  But beneath them all—at least at first glance—there are also slaves.  Most slaves had previously been captured outlaws or prisoners of war.  But their numbers also include a minority of former freemen who willingly sold themselves into slavery to spare their families from the burden of debts they'd accumulated.  Others were sold as children by parents who had more mouths to feed than they were capable of providing for—who otherwise would have been exposed to die in the wilderness, out of necessity in the brutal reality of Tamriel.  

Individuals who have the resources to do so may take on the responsibility of rehabilitating those whom the state would otherwise have no choice but to discard—of turning outlaws, deviants, and misfits into productive contributors to society.  Some slaveholders doubtless abuse their position and sadistically mistreat their property—we see no different with dogs or horses on contemporary Earth—but this is not the rule.  Of course, exceptionally few if any get into the slave trade for purely philanthropic reasons; even benevolent slaveholders expect to derive benefits from their charges.  But most view their slaves much like a rancher might view a horse.  Yes, some harsh treatment may be necessary to break a wild filly, but the rancher takes no joy in hurting her.  It is simply what must be done, both to make her useful enough to her owner to justify the resources expended on her, but also to protect her—and others—from herself.  Remember, if she were to escape, she'd face execution by the local jarl or death in the field at the hands of Tamriel's many soldiers and bounty hunters, not to mention that she'd be liable to kill innocent passers-by along the way, so even a most compassionate owner knows she must break a rebellious slave to the point that she is no longer a danger to herself or others.  But those slaves who learn to embrace the lives their mistresses can offer them may look forward to long lives as beloved pets, valued servants, or for a lucky few, even trusted companions on the battlefield.

Once the shock of enslavement has passed, old criminal habits have been broken, and the slave has had time to reflect upon her situation and its likely alternatives, most do come to accept their lot and seek to make the best of their new role.  Some doubtless remain bitter at the injustice of the world, but most accept things for what they are, and some even show sincere gratitude to their mistresses, at least for the opportunity to avoid the headsman's axe, and perhaps even for the role their new owners have given them.

Whilst there will always remain a clear hierarchical gap between slaves and their owners, this doesn't prevent some slaves and slaveholders from coming to see one another as essentially family.  The slaves have more burdens and fewer privileges than the free members of the household, sure, but they too are members of that household.  In a well-run household, every member—both free and bound—knows exactly what her responsibilities and privileges entail.  Slaves know precisely what they must and mustn't do, precisely what consequences they face for misbehaving, and precisely what privileges they can look forward to if they behave well.  And they know that Mistress will always protect them, provide for them, and treat them at least fairly—perhaps even kindly—so long as they perform their roles faithfully.  Exactly what form this takes will certainly vary from one household to the next, but for example, a slave who has finished her chores likely dines with her owners, perhaps even being lucky enough to kneel by Mistress's own seat at the table and eat directly out of Mistress's hand!  Trusted slaves typically no longer need to be caged at night, and instead may sleep next to or even right at the foot of Mistress's bed!  Although slaves certainly aren't allowed to go where they please, loyal companions can look forward to being taken to accompany Mistress to visit many exciting locales!  Slaves have no property rights of their own, but if they're very good girls, Mistress is sure to reward them with luxuries that only they may use, like soft cushions, proud shiny nametags, and big knobbly dildos!  

Although, officially, every slave is equal in social status to every other—any slave may be bought and sold at will—in practice, the favourite slaves of a high-ranking mistress may enjoy many privileges that lower class freemen could only dream about.  Such pampered pets eat sumptuously—within the limits of maintaining their figure, of course—sleep in luxurious quarters, have access to the most exclusive areas of cities, and dress in only the finest collars, cuffs, and buttplugs, all whilst working much less... well, slavishly than the typical farm hand or miner.  And any children born to such slaves are likely to be fostered by the family of their mother's owner, growing up to live as freemen who may pursue their own fortunes in middle-class life—perhaps even able to purchase slaves of their own one day.  

Moreover, while it is certainly true that slaves enjoy fewer rights than freemen, they are not wholly without legal protections.  The law considers that enslavement gives a person a clean slate.  New slaves do not carry any previous warrants, bounties, or debts with them into their new station.  Owners have broad but not unlimited latitude to use corporal punishment in training their slaves; they may beat them, bind them, rape them, and deprive them as necessary, but slaveholders are not permitted to intentionally permanently disfigure their slaves, such as by amputating a foot to prevent flight.  Slaves may be bought, sold, and traded at will, but their owners do not have the right to summarily kill their slaves without cause; the criteria for capital punishment of slaves are quite similar to those for freemen.  Children of slaves are legally the property of their mothers' owners—although freedom for children is a common reward for loyal slaves—and both mother and child may be sold, but owners are not permitted to sell children separately from their mothers—they must be packaged together. 

So, as you can see, life in Antiope's Tamriel is tough, and no one is under any illusions that they're building a utopian society.  Citizens face many brutal realities.  For many, a slave's life certainly beats the alternative, no?