I think it's just the camera angle that makes it seem like the plaque is much higher up than it was in TNG.
Yes, SPS has shrunk a bit, it's a natural event, plus he's extremely upright in the TNG shot and in the Picard shot he's hunched slightly...again..the man is 82 years old vs 52 years old he was in the TNG shot.
Yeah -- men shrink after 50. It's a well known fact. Not a production error.