Vader at least picks up the item he was considering, still debating if he wants to take it with him or (attempt) to down it here. But he takes the nudge for what it is. Not warm but not shutting him out either.

He considers the empty chairs, before selecting one he doesn't believe will creak or groan under his weight. And he's uncomfortable sitting so casually in public, that's clear from his presence in the Force even if he masks it extremely well otherwise. The expression is something that makes him feel vulnerable.

"It is relieving news to see you looking so refreshed." He doesn't remember how to a person at this point, don't squint too hard at him.