Blood rushing to the surface of the skin when you're embarrassed seems to be a near-universal trait for species with circulatory systems similar to humans. She doesn't stop Megamind from retreating up into the crawlspace, but she also doesn't leave the vicinity of the lair.

Instead, she starts taking a look at all of the things that he's got going in the lair: the breaking and entering tools that he's working on (for Kasumi, based on their earlier conversation) for one. Nobody who's clueless about the art of thieving would be able to make tools like this -- so that helps explain why he doesn't like feeling caged up.

Huh.

No, really, she's not going anywhere. She'll just wait until he's done hiding.