> aiui, the X protocol REQUIRES that the video display is copied between the client and the server SEVERAL times. If both are on the same machine, no problem. It's easy (and has been done) to do the copy by passing a pointer. Quick and simple.
It does not. Quite the contrary it encourages you to pass your images to the server and manipulate them using "pointers". And of course Xorg has local display optimisations. It's up to the application what and how to draw. A lot of small unique images to pass over the network may slow down the whole process, as many modern themes do.