I like the not-quite-determinable expressions -- they reflect the sorts of not-quite-determinable emotions I've felt in situations like these. Like he doesn't know if he wants to run to her or run away, yell at her or kiss her. Torn up inside. That's what I read. I get the impression he's just a moment ago turned towards her starting to say something, then turned back aruond before she saw and clammed up, not sure if he should say anything at all.