I think for most it represents another way to give up control. Letting go of your ability to see, is another way of submitting. It can also bring up emotions like fear, anticipation, teasing and so on. I think most Dommes who blindfold are doing it to play with these types of emotions. I believe most Dommes use a blindfold in an attempt to add this type of excitement to a session and it is totally well meaning.

I think the OP is concerned it might have the opposite effect. That not being able to see the gorgeous sexy Domme in the room with them may be a bit disconnecting in the session. I think this is true for the first few sessions with a Domme. Typically, I've not liked blindfolds for just that reason, I want to see who I'm enduring for and I want to see how happy she is at my suffering. There is no bigger turn on than seeing the joy in a Dommes eyes. So there is a bit of a disconnect, especially if we are establishing our S/m dynamic when the blindfold goes on.

That being said, sensory deprivation (sight in this case) can be a wonderful tool when the S/m dynamic with the Domme is established and strong. Under those conditions I was recently subjected to a tight, restrictive full rubber hood with no eye or nose holes and only a tube for the mouth. It was very claustrophobic in there and a bit scary when she put her hand over the breathing tube or tortured me in other ways. But the fact that we had such a strong connection made it an amazing experience. I was able to let go and endure this form of torment for her. And while I couldn't see her, I could hear her enjoyment of my predicament, which made it so, so sexy.

My advice is that if you are hesitant about something like a blindfold, mention it. Say it's something that you need to work up and might feel comfortable with after you interact a bit first. You don't need to pepper her with a bunch of emails, I shoot for one or two to discuss interests and only write more if I'm asked additional questions.

Hope this helps.