Some VFX appear very pixellated compared to every other VFX in the game when playing at 2560x1440.
TO REPRODUCE:
Load the saved game attached on a PC whose monitor's native resolution is 2560x1440, and play at that resolution.
Walk east with your party, as though heading toward Caed Nua.
Near the edge of the map, the protagonist will have a vision with two souls chained to slabs and tortured.
When the souls disappear, observe how the VFX is very pixellated (even without zoom, though zooming in will of course make it more apparent).
SAVED GAME: link
(For some reason the forum won't let me attach it.)