Boxing selects for Jon Jones type physiques -- skinny legs, thick torso, long arms, and tall. Cameras are 2-d images. So, you can see height and length but you can't see thickness. The taller guy will always look bigger in a photo.
In person though, you see the thickness that photos and videos don't show. Cain doesn't look that big in pictures because he's only ~6'. I saw him in person once though and the thickness was unbelievable. That's the same way that Tyron is built. And DC. Guarantee all you guys that think DC is small would be like holy shit if you saw him in person.