He does it a lot, actually. I’m fairly convinced it’s a sign that he has a disorder of some sort as discussed in this salon article from 2020.

“While most frequently observed in Parkinson’s Disease, the bent posture so evident in Trump may also be seen in Alzheimer’s Dementia, movement disorders of the basal ganglia, and as the side effect of certain medications,” Cytowic continued. “Also noted are the sudden, jerking movements of Trump’s right arm. Since they occur only on one side, the prefix “hemi” is applied, while “ballistic” means sudden or flinging in the manner of a projectile. Trump’s hemiballistic arm movements are evident in news clips from Memorial Day (also here via C-Span) at the Tomb of the Unknown Soldier, as are his uncontrolled swaying and forward tilt. He is seen to grab his wayward arm with the left one in an effort to keep it under control.”

Youtube video here. You can see he stands with the same kind of lean (starting about 0:30) and keeps wobbling the whole time. The wobble gets very pronounced after he walks up to the wreath (around the 2:15 mark). As for the arm movements described above, you can see some good examples starting after the 4:15 mark. There’s also an earlier point at the 2:28 mark where you can see him suddenly clench his left hand on his right wrist as if to hold it in place.

I really think the man is not well and he is basically a puppet for the far-right and all those billionaires.