I had one of those tall shelf units meant to go over a toilet, for towels and such — and I had no real place for it. When I looked at it closely, it had come in a short box and the legs had been assembled tent-pole-style and attached with screws. I took the top part off of the bottom part and voila, it was really shallow in depth and just the right height to go over my pop up sink for a toothbrush cup, makeup mirror, alarm clock, etc.
The legs were sharp metal at the bottom and it obviously would have to be removed to fold up the ‘pup, (fits beautifully under the table area) so I bought four white rubber feet slightly larger than the shelf posts and stuck them to the countertop with removable “Command” hook adhesives. (I fear commitment.) So the unit can be placed in the feet and won’t scoot right, left, front or back. It lifts out when it’s time to roll.