Well… the box on the left is slanting and the calendar (Oct 2020) and this thing above it isn’t directly on the wasll (see clip)… the ceiling is slanted because the camera wasn’t totally horizontal…
Also the looking direction may not be toally parallel to the room and/or the camera position wasn’t in the center… if it would be then the vanisshing point would be in the middle…
But would and could… you know what i mean 
(Also Photgraphers usually do plan this 
)
By the wasy there was an amazing tut about fSPy how to really understand how to use it…