Ok on to this Mewtwo shot:
Now I will be comparing this to both Melee and Project M renders, first up Melee:
The distinct differences between this Mewtwo and his Melee render are the following:
1. No Mouth or Nostrils might just be bad photo quality
2. The tube that connects the head to the neck has A. different angle at its starting and ending points and B. A completely different curve then Melee and this is not a perspective thing. Also the Tube looks thinner.
Next onto Project Ms Mewtwo here is an ingame screenshot that is the closest I could find to resembling his pose in this CSS:
Once again there are a few differences such as:
1. The Eye Color is darker but this could be easily edited
2. Once again the Tubes is thicker and the curvature is not like the leaks.
Reasons to Discredit this leak:
1. That weird half circle on the right of the screen.
2. Bad Picture Quality
3. Off Information in the Post
EDIT: Also Mewtwo has a smaller head in this in comparison.