The image with your finger in the shot is where the incoming external copper cable appears, it’s cover is the original one that had a hard wired corded phone (old style rotary dial phone) , that’s why it has a square ‘hole’ in the centre , someone has connected an extension cable to the external cable to connect a modern style plug and socket phone , often the new socket is placed next to the original one with a very short cable between, obviously a previous occupant wanted the telephone on the opposite wall to the original cable entry point.
If that incoming copper pair is still required because FTTP isn’t available, then the external cable needs to be maintained , you could simply shorten the extension cabling and fit the modern socket next to the original cable entry point if you don’t want that lose cable on the floor , or look to somehow fix a modern faceplate to the original back box (connecting the external cable directly to the faceplate)
You should check if FTTP is available to the address , if it is then it’s all the copper cabling becomes redundant anyway .
