Presidential pix

Several questions, revolving around the practice of putting up photographs of the Pres and Veep in the entrance of the various Federal buildings:

When did this become general practice ? [I suppose it was portraits earlier…] What happens to the old photographs ?

Presumably, they’re taken by some official photography office in the White House. Who chooses the final print ? [The current vice-presidential photo sports what can only be described as an odd, unbecoming smirk.]