Have you tried putting your phone on video and holding it like you are talking on it? Then edit a single frame out. Or hold it to take a still picture but say at that time something about hang on a sec, I have to hang up this call, then hit the shutter button on your screen like you are hanging up. Or take it just shy of the window when they are busy, or when they turn away to get your fries. Pretend you're talking on speaker phone and don't act like you are taking a picture. This should work most of the time. For me, careful video is the best usually.
Doing my best, every day
Previously blocked poster using new name. Poster and post removed.