Same. Plasma tv (panasonic vt60). Many years old, no burn in.

Cell phone is Samsung OLED. No burn in.

I'm sure it's a thing folks have experienced with their plasmas and OLED, but I haven't made any effort to reduce persistent logos or images, and with just regular usage haven't had a problem.

I was guessing it was to show that the clip is being run at real time, since you have a pretty good idea what steam dissipation looks like.