The angle of this photo is particular. When we later see this room (Derek's room), with the stepladder to serve as a scale, we realize that the photo was taken from the ceiling-wall corner.
Jacob wouldn't have glued his phone to the ceiling to have a sextape with Arieth. He would have put it on the chair, on the stepladder or whatever, but not there.
I see two explanations:
- DPC made a mistake on the angle of the image,
- there is a hidden device in this room (at the corner of the ceiling which is a place that is off-screen every time we see this room in the game)
If we take the second hypothesis, a device hidden here, it is not innocent. This is the place where people go to fuck at DIK parties. This is also where Sarah takes us for a meal at Quinn's restaurant ...