The red piping on his pants, that precisely parallel the visible edge of his penis shaft, is where the photoshop alteration took place.
The length of that piping, where it oddly matches the the exact curvature of his dick, is how much was added.
Stop being so gullible and LOOK at what you see.
if you take off the portion that was obviously added ( about 40% of overall length in image ) that still leaves him with about 7" of flaccid length.
Which is pretty big.
However, chances are he is of Hottentot or related ancestry, and has the genetic trait of steatipygia... which would mean that his genitals when flaccid are actually semi-engorged... meaning when flaccid his genitals remain 80-95% of their fully erect dimensions.
If that is the case, then he is likely around 8 to 8.5" fully erect.
Which is what a REALLY big dick generally is. ( as opposed to the inflated figures most well hung men throw around, that are insupportable in reality. )