Do you mean the camera being used to cover Mariko went into a menu mode showing thumbnails of clips?
If so that's a result of the camcorder going into replay mode (to allow you to watch rushes you've already recorded, either for review or playout purposes). You see it happen occasionally on live feeds, but usually when the camera operator believes they are no longer on-air.
Nope, it popped up a Yes/No option (where the options were Ok and Cancel) with the question being like "Some data on this memory card needs to be recovered. Recover? If you don't do it now, you can do it later" or words to that effect. After that had been shown on screen for about 5-10 seconds, it went back to Kasia in the studio, before going back to Mariko a minute later.
That sounds like a standard OSD overlay then (rather than the full-screen UI).
Some cameras have two outputs (one with the OSD, one without the OSD) or a menu option to enable or disable the OSD on the external output. (If you are plugging in an external viewfinder you want the OSD, if you are plugging in the camera to an external link device, you probably don't)