...And is also depicted on Archer's ready room wall. It's the outline of the real CVN-65, the real world's first nuclear carrier, and the square island belies the outlines of a long-outdated radar system typical of that vessel.
The thing is, in the Trek universe, CVN-65 was played by another carrier, the conventional CV-61 Ranger, which has a completely different-looking island. It was never played "live" by the real nuclear carrier.
So we can basically do three things:
1) Yell "Yet Another Trek Inconsistency!", which is a bit boring.
2) Say that the Trek universe featured at least two different nuclear carriers named Enterprise, one with a cubical-looking island and one with a conventional island, which is only half a solution because artwork depicting the cube-island ship has featured the lettering 65; there shouldn't be two different carriers with the same number painted on the flight deck!
3) Say that the nuclear carrier CVN-65 was refitted during her service life, either from having a cubical island to having a conventional one, or vice versa. The other external differences between the real Enterprise and the Ranger are minimal, after all, and could be covered by a rather minor refit.
Since most commemorative artwork depicts the cube-island ship, one might assume that this was the final configuration of the vessel. OTOH, it may have been the more famous configuration; perhaps the Trek CVN-65 fought her best and bravest battles in that configuration, before being refitted?
Similarly, the NX-01 is depicted in her TV show guise in the commemorative artwork of ST:NEM - but that doesn't necessarily preclude the idea of a major refit in 2155, as many fans would appreciate (because there were some plans to do such a refit for the fifth season of the TV show, before it became clear there'd be no fifth season)... We might simply argue that the artwork commemorates the configuration in which NX-01 saved the Earth from the Xindi.
How this might relate to Picard's space station is uncertain. The subject of the painting might be important to him, even if such a structure was never quite built in that configuration, or was quickly modified to some other configuration (say, the particle fountain of "Quality of Life" which is the closest thing to that painting we can find in aired Star Trek). Then again, the painting itself might be the important thing. Perhaps Picard himself painted it? Perhaps a friend or relative of his did? Perhaps it's a hideous generic commercial piece of work, but the person who gave it to Picard was special to him, and he wants to remember that person through the gift?
Picard didn't write Shakespeare's works, and AFAWK didn't pursue an active career in acting, either. He still has the Bard's collected works in his Ready Room. The rest of the decoration might be similarly detached from his person.
Timo Saloniemi