Olivia watches Steve out of the corner of her eye, just enough to keep him in sight without invading what little privacy is possible even in a park this small in Manhattan. She's not watching him out of impatience - she's just concerned, in a half-conscious, completely illogical way that she's going to blink and he'll vanish, and then not only has she lost the one person here really invested in helping her, but she has to explain to SHIELD what the hell happened. All in all, maybe best if she just keeps an eye on him.

When she notices someone approaching him, though, she turns to look straight at them, expression suddenly intent. She's not about to head over just yet - maybe the man's a friend, and even if he's not, Steve can probably handle it on his own - but it's obvious the Captain wants a moment to himself just now, with whatever this is, and something in her bristles at anyone invading that.