From appearance, these look the same as membrane keyboards. Actually it’s a simplified membrane switch, where the underlying wiring is replaced with a printed circuit board (PCB).
In a normal membrane keyboard, the wiring is made of polyester, with screen-printed conductive connections. With contact layers, the foil is attached directly to the printed circuit board, and in this way makes contact with the connections on the PCB. There are not necessarily graphic differences between the two solutions.
Contact layers are a reliable, compact and economical alternative to full-fledged membrane keyboards.