I don't know - the majority of his photos look fake/shopped/camera trickery to me.
The few in which he appears to be "smaller" are likely the only legit pics in his gallery.
I agree that there probably is some kind of fakery going on. There is quite some difference in size between those two photos.
The one above where he's lying on his side looks "normal" but the one below looks like it's been morphed in Photoshop a bit and could almost be a completely different guy's junk altogether.
From a personal perspective, there are times when my own dick varies wildly both in length and girth and I'm sure yours does as well. As masonjames correctly says above, it's all just a matter of how much blood is flowing to it at any given time.
There are some rare occasions when I'll wake up dying for a piss and I'll have a boner (fucking hate it when that happens as I'm sure you would agree) and after I've finished, I look down at my semi and in the mirror and it looks not too dissimilar to the bottom photo and that's coming from a guy who would describe himself as decidedly average when it comes to size.
Like I say, that's only on vary rare occasions. I certainly never vary in size to that extent on a regular basis which leads me to think that there is perhaps some Photoshopping going on.
Anyway, as I say, I don't really mind either way. I love cock and his is amazing in all of his photos and videos big or "small".