I believe that both parties agreed to make the meeting low key. There are a few photographs knocking around, taken by Beatles Book photographer Leslie Bryce.
The meeting actually turned out to be a non-event. Paul says that Elvis was sat fumbling around on a bass guitar and that he was very quiet. Strangely, so was Lennon and it appeared that both camps were in awe of each other's presence.
There is certainly no mention of any jam session and I think Elvis felt somewhat uncomfortable and out-numbered by the Beatles.
Thus, the lack of photographs and the fact that this meeting is rarely mentioned shows what a disappointment the whole episode was.
(Obviously, my input here is from the perspective of the Beatles. I would imagine that there could well be some photos taken by Elvis's clan but again, the fact that no-one's seen them probably means that Elvis would sooner have forgotten all about the meeting. Indeed, rumour has it that when the Beatles left he was quite nasty about them.)
For the good life is out there somewhere