I told Trump he was full of...
This is another Joe Biden meme - The humor in this meme is similar to most Joe Biden memes - they are insinuating that Biden is not particularly smart. If Biden mistook some random construction worker with an orange hat for Trump, then obviously he is not too bright.
Obama is playing the straight man in this meme - and that makes this an Obama meme as well.
This might also be subtly also calling Trump's face orange (which is a pretty common trope in Trump memes), but it isn't 100% guaranteed that that was intended, or if they just picked the color of the hat at random.
I don't really consider this meme funny - I have seen much better Biden memes.