They are different meanings and the first sentence is probably incorrect.
The meaning of deign is similar to agree.
: to condescend reluctantly and with a strong sense of the affront to one's superiority that is involved
We can clearly see that "agree not to look" and "do not agree to look" have very different meanings.
"I don't want you to look at me while I'm undressing. Do you promise not to look?"
"Yes, I agree not to look."
"I want you to look at this painting I made. Will you look at it?"
"No, I do not agree to look."
If we ask, "do you deign to look at me?" the question means will you look at me, even though you think you're too good to do so. The answer could be "Yes, I deign to look at you," which would mean I agree to look at you, even though I think it's beneath me; or "No, I do not deign to look at you," which would mean I do not agree to look at you - it is indeed too far beneath me.
If we ask, "do you deign to not look at me"...well, it's not clear what exactly this would mean. It is unusual to condescend not to do something. Perhaps it could make sense with some other action: perhaps it's impolite to question a superior, even when they say something unreasonable. Then, perhaps an inferior could say to his superior, "Would you deign to not question me?" It's a stretch.