It's just a trope in anime.

It's not awkwardness as much as it's trying to convey everyone's brain short circuiting for a moment.

Awkwardness is usually represented with sweat on the forehead/temple area.

And then you get stuff like jittering eyeballs conveying extreme stress, or long internal monologues occurring within half a second in the middle of combat.

Anime literacy to the rescuuuuee