What visual changes have you noticed that happen on gameshows "when you're not looking"? That is, physical changes that clearly took place before the camera, but we rarely, if ever, see it happen; it always takes place either during the commercial, or when the camera is focusing on something else, like during a fee plug. Stuff you may have wondered what it looked like.
Examples:
TPiR: putting the labels in the showcase podia indicating which contestant bid on which showcase. Also, inserting the little price tag in the pocket on the side. (On the nighttime Dennis James version, this was done while the second showcase was being shown, since there was no commercial between that and price revelations.)
Newlywed game: putting the answer cards on the contestants' laps. Also, when the husbands and wives disappear, although the latest version actually shows the wives getting up to leave, at least at the beginning.
Jeopardy!: Putting up the dividers between the podia for Final Jeopardy! In the Art Fleming version, they also put up those fold-over cards to write on. (With a Goodson-Todman asterisk on the front? How'd that get there.)
What's My Line: Putting on the blindfolds
Concentration: Returning the board back to numbers after puzzle solved. Though in the syndie version, we'd usually hear all the trilons reverting at once; not sure if that ever made it on camera. In the Bob Clayton version, we'd sometimes see the doors close between rounds, done to music in fact, but other times they would suddenly be closed at the end of the Chevy Nova promo.
Wheel of Fortune: Setting up a new puzzle, before the electronic board debuted. Also, putting special items on the wheel.
And there are any number of shows where an electronically-based display would revert, but seldom or never on camera. Such as the Hollywood Squares board de-lettering after a win, the TPiR single-bid displays clearing (other than when everyone overbid), etc.
One that doesn't count is the individual score displays on the 10k pyramid (and others?). Did anyone else ever notice how, while the contestants walked toward the winner's circle, the numeric displays sequentially cycled back, i.e., they went 33, 44, 55.... 99 then blank? I used to be puzzled why the display could go that high since the contestants could never score that much, even if they got every clue right.