The speculation that Zuckerberg would be entering politics and probably pursue the presidency date to long before the 45th presidential election.
If memory serves, it goes back to when he began visibly embracing a particular religion, in contrast to a previously atheistic stance. It was pointed out in the media that this transition often occurs in the preparation phases of entering politics to attract votes.
I don't think he was disparaging his looks, but rather his social skills. It's undeniable that Zuckerberg is not really an extroverted social butterfly with good public speaking skills, which is kind of a requirement if you want to get into politics.
During Bush's funeral I saw 4 respected, graceful presidents, and an orangutan. I won't comment on Trumps image or qualities as a president, however he clearly doesn't have hollywood looks, or even good looks.