He just looks warm to me. The testicles are very mobile within the scrotum and move up and down depending on how warm and or relaxed the hamster is. They can look like peanuts pushing through at odd angles sometimes. Does it look grazed or scraped at all? Does it feel hot and tense?
Infected testicles are very obvious and very red, hot and swollen with a hamster in obvious pain.
Keep an eye on him but at the moment he looks all right to me. The rear vent is his anus and the further forward one you can see is where his penis is and where he wees from
