When an experience orb or dropped item is sucked into a magma block water column (its expected to be sucked into it because its an entity) it doesn't stay on the magma block, it starts to flow up but then the magma pulls it down again, making it shake

video: https://youtu.be/P8Fk2RvtUG4

how to reproduce:

1. Set up a magma block with few blocks of water source blocks on it
2. Throw lots of items onto the water or throw experience bottles
3. Quickly switch into spectator mode so the experience orbs don't follow you anymore
4.  If you look closely the experience orbs or items shake