In Flash, every time we see the man-in-yellow, he's always vibrating constantly. Like this:
Admittedly, it looks super scary and ominious, but what's the logical reasoning for why Eobard Thawne chooses to vibrate?
And why do his eyes turn red? Barry's didn't do that when he vibrated his face, but every time Eobard dons his mask, it lights up...
Note: I'm referring to DC's Flash series.