A hook is a small promise: this thing will not be on the floor tomorrow.
How it grips
A flexible backing plate spreads the load across 40cm² instead of four screws, which is why it holds on plasterboard that would crumble around a nail.
Where it works
Painted plaster, tile, varnished wood, metal. Not on wallpaper, not on fresh paint under seven days.
Removing it
Slide the release tab, and the plate peels off without a tool. Patch not required.