In this way, Tess overlaps with the object.
In my personal opinion, when Tess moves using the door, it usually appears to be summoned above the floor and fall, but in some sections it appears to be created by sticking to the floor. It seems that Tess and the object overlap during this process.
And if you put the UV light on the monitor in the secret room where the plague doctor is present, it becomes like the picture.