He hands the phone back to Scott at the end. The dick is identical to Scott's several already leaked nudes (i.e., he isn't careful), down to the rather identifying details of the head.
It's probably Scott's, much as I'd rather it not be. Don't see how that's "conspiratorial."
Actually an impressively awkward situation for Chris if so, as he's now probably intimately familiar with his brother's dick, since it's being passed off as his. And he can't say the reality without throwing his brother under the bus further... lol. Really sucks for both of them.