This is a popular 90's trope where the director decides to increase the tension before a cut to commercial by doing an ECU on a character. That character then needs to make a "holy shit you guys, there are real stakes here" or "whaaaaa?" face for 5 seconds or so.
It provides the viewer with some great meme-able screenshots.
Characters notably good at this: Worf, Riker, Kira.
Characters notably bad at this: Geordi, Lwaxana.
A closely related phenomenon is "Eyes to Theme", which can occur if the episode has a cold open.