From my experiences, indifference is one of the most hurtful feelings that a sub can encounter in D/s. It feels like she doesn't care about it, it isn't important enough, etc. It feels lonely and awful.
On the other side of things, my subspace is fueled so heavily if she acts dismissive. I consider this a bit puzzling, but it fits into my views on control and my anxiety related to being rejected or abandoned.
To vanilla eyes, being dismissive probably looks more cruel than being indifferent, but from a submissive perspective it makes all the difference in the world. It's hard to describe but having her treat aspects of me like they do not matter feels better than not caring. Simple phrases are often enough to push my subspace into a frenzy of turmoil.
- "I understand your feelings but they don't matter."
- "Since when does what you want have any importance?"
- "It's cute the way you think I care about that."
Actual indifference is awful. It sucks the life out of a sub. When you truly feel like what you do does not matter, it is hard to feel like you matter. Being acknowledged brings about such a difference... even if her acknowledgement claims it doesn't matter.