I think that image is altered. Why does the ruler start out on the top in centimeters/millimeters and after her fingers change to inches? If you look at the dick itself, it looks like the shadows might be off. There's a lot of light to eliminate the shadows as a point of reference. Shadows are usually what out digitally altered pictures.
If you steal an eighth of an inch here, there, and everywhere, you can exaggerate a good bit...it's even more convincing if you grab millimeters instead, and spread it out.
Her fingers look off, too. Can't put my finger on it, but the proportions just don't look quite right. Also, the sides of the penis look too crisp, like they are superimposed on the rest of the photo, like a stretch tool or something for a selected area.
I could be wrong, but it's not like the porn industry has a vested interest in being truthful, so I doubt it. It's a high quality alteration, so they are obviously hiding something for marketing purposes. Their job is to sell lies and fantasies, and they obviously invest vast resources in that.