He's more vascular now and his skin is clearly starting to show age and ill-effects of weight gain and drop. Similar to some pro wrestlers as they age.
However, part of the difference in those photos can be attributed to his moving up 20 pounds to fight Jones and then cutting it. Clearly he held some mass from his venture to 205.
I'm not saying it's all on the up and up but someone who bulks up an additional 20 (even 15 or 10) would show better muscle mass when they dropped back down; especially at a weigh-in where they are dehydrated.
You say shark I say hey man, Jaws was never my scene and I don't like Star Wars