Marvelous! Thank you, dlbkelly_cfl_rr_com and the rest! I used Bostik Dimension diamond urethane grout which I’d used before with little issue, but I apparently waited too long to wipe AND since I had varying tile thicknesses this time -- I had the clever and time-consuming idea of combining 3 different styles/brands of tile sheets -- there was more residue to clean off. My glass -- regular, polished and frosted -- and stainless/polished steel mosaic tile looked horrid. Sadly, I used the manufacturer’s suggestion of Windex and that made the area’s grout I tested just a tiny shade of bluish white instead of brilliant white - only noticeable to me but still annoying. A half-vinegar/half-water concoction worked with the bulk of the thinner residue and I finished off the thicker bits with a razor blade/glass scraper (only on the glass); the glass scraper was necessary for the frosted glass tiles but I will go over it again with a pumice stone or magic eraser as was suggested elsewhere for matte tile. The brushed stainless tiles are giving me a hard time and the polished metal tiles did get scratched by the grout/ocelo no-scratch scrub and wipe sponges but a huge improvement! If this hadn’t worked, I’d have to run out and get the Bostik Blaze which is also good for urethane grout haze clean-up.

I need to remove a bathroom vanity to repair the wall. The vanity installers tiled around the base. Is there a way to temporarily remove the vanity without tearing out the floor tile?

You could always grind the surface down (the ENTIRE lot). The prints are now 'in' the concrete. I'm guessing the weight of the foot/body caused a slight change in the SURFACE of the concrete. This would have shifted the direction of the surface aggregate to have a different look. Kinda like vacuum lines in a carpet. The direction change of the pile changes the appearance of the carpet. When finishing concrete the pros sweep it or 'brush it' to give it a specific look. I'm guessing your body weight disturbed this brushing enough to cause a visual change. Technically there is nothing wrong with the concrete...but it is an eyesore.

I would have a professional come in and polish and seal the floors. Also, do you have a good fan in the bathroom. I don't wipe down my shower floor or walls but my fan runs automatically based on humidity sensor so my bathroom is dry including shower floors, wall and door. Also my understanding is that marble needs to be sealed once a year. I just finished a remodel which includes marble floors in shower and bath and was told that sealing annually is part of then normal maintenance.