Where does the smoke (or vapour?) in engineering come from?

In Star Trek Discovery, episode 3×09, there is a scene about 16 minutes into the episode where Stamets is in engineering. The computer announces: "Video rendering complete", whereupon Stamets steps over to a computer terminal.

In the moment when we see Stamets looking (from the viewer’s perspective) to the left, while the terminal is just about out of sight on the left edge of the screen, some smoke is rising from the terminal:

Where does that smoke/vapour come from, and why is no-one bothered by it?