Yes, indeed... There is blatent mindfuck and manipulation in D/s relationships. And it's not one sided, either. The point is that it's almost all geared to strengthening the bond between the participants.
Let's say, purely hypothetically, my sub has discovered that I become much more tender and affectionate after she spends 10 minutes sucking my balls. Let's say she's the type that can't get enough affection. Guess what her second favorite activity, after receiving that affection, just became...
Yep. Inducing my affection. By the most reliable means at her disposal.
Now let's say I really really like having my balls sucked. And I know she's eager do anything for a little affection. And I tactically let her know that my mood changes when she's hungrily wearing her ball gag, which happens to hang between my legs...
Who's playing who? And does it matter, since both are getting what they need, and becoming more intimately attached to their partner, who is providing it?
Submissives serve, wanting to please their Doms. I'll speak for myself as a Dom, I reign, requiring my sub to become ever more attached and devoted to me. And I train my subs with Pavlovian conditioning and seductive mindfuck to do it. Because the ties that bind are not made of rope or chain.