Most cats love anything shiny and wiggly, that they can paw and scratch at.Since water is reflective it can be a source of entertainment. Stainless steel dishes can reflect shine on the floor or the wall if that’s where the dish is placed nearby.
A a cat that scratches or paws around his water dish might do it as his own drinking ritual. They might also paw around their food as a sign of pleasure, so they might be kneading the floor before and after drinking.
If your cat’s water dish is too narrow it can lead to “whisker fatigue or stress” because of the pressure being put on, pushing back, or squeezing the vibrissae together. This may cause your cat to paw around and inside the water bowl.
One of the things cats will use is their paws to claim their territory, thanks to the scent glands located there. By scratching the floor around the water dish, cats claim that area and let the other cat know not to drink from there.