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.
That isn't his official portrait though, is it? I recall that image being used in 2016 before he won.