I get most of what you're saying about Grober's piece, although I don't think the prison window echoes itself. Maybe you meant the mayo wrapper is echoed in the lower rectangles?

Also find your 'wide stance' assertion a weird reach. As a man, if I do not force my feet together to stand at attention, but naturally place them roughly underneath my shoulders while standing, that is about the proportional space you would find between my feet. It is nowhere near being so wide as to creep into the next stall while sitting down in an airport bathroom.

As someone who does draw sometimes, it is about where I would draw my feet, looking down. Doing so would not be an oblique reference.

The shadow seems to support my belief that this is just a regular man's foot position, when standing. Notice that you can see his right hand's shadow extend a bit past that of his right foot. Notice also that you can see his head's shadow in a way that doesn't really seem to match the idea of sitting on a toilet, especially because the light source is behind and above him, which makes no sense for a toilet stall.

Also, Grober would have had to have been prescient, since the drawing was done about 5 years before the scandal to which you mistakenly impute reference. Is it your position that Mr. Grober is a precognicent psychic because the man's feet he has drawn are perhaps wider apart than your own tend to be?