Hmm they could be placed on top of each other but there would be a degree of "adding" information to one of the pictures.
The pictures are totally different angles, focal lengths and focus points. You would have to majorly change the information within one of the pictures to make them line up one on top of the other... and I think any lawyer would argue the photo is no longer original.
The key point in what I did is circle patterns that appear in both shots regardless of angles, focus etc..
-----------------------------------------
My understanding, is that in one of the pictures, an attempt may have been made to clean the bloodstains up, but that whoever tried to do it with a view to trying to eradicate the blood evidence, did not make a very good job of it...
Hence...
The very light traces of where the blood staining, originally existed...
Let us also not forget, that Essex police cut this piece of carpet out from the remainder of the bedroom carpet, and they burned it on a bonfire in the grounds at whf...