If you wanna get deep into the weeds, Trump's portrait might give away that he won in 2016. He wouldn't have had such an official-looking portrait taken in front of the American flag otherwise.
Come to think of it, the (b) after Florida might give it away too (or, at the very least, give away that he'd previously been nominated while living in another state), given how the Nixon CA/NY situation was handled on the 1968 election's wikipedia page.
Also that's Biden's official VP portrait taken in 2013, and if he were an incumbent, he'd presumably have a more recent photo.
(Note that in the article today it shows Biden's official 2021 presidential photo, with the off-center tie most cropped out.)
