I am not going to claim that Donald Trump literally has lost control of his body to the point where he needs to wear diapers. There are some indications that this might be the case, but I am not going there, because it really doesn't matter other than as a possible secondary sign that his decline is partly due to dementia and not just psychosis and outright stupidity. No, the headline is figurative. Let me explain.
Today, Donald Trump tweeted a photo of himself wearing a mask, after months of refusing to wear one, and tried in a pathetic manner to claim this as proof that "your favorite President" is more patriotic than anyone. Sorry, Donald Trump, you get zero points for coming this late to the party. In fact, we think you should have a few points deducted, but you are already at zero, so we'll award you nothing and call it even.
Lindsey Graham, one of the most sleazy of the Republican scum in the Senate, tweeted "Well done, Mr. President", as if praising a toddler for finally pooping in the toilet. However, the picture was from Trump's previous visit to the Walter Reed hospital, where he was required to wear a mask to gain entry. What's more, minutes after the tweet he went ahead and held a meeting where nobody had a mask on. Therefore, Graham's tweet was more akin to congratulating a nine year old for finally having been forced to use the toilet once a few days ago, but now continuing to poop his pants just like before.
Whether Donald Trump actually poops his pants is largely irrelevant, but metaphorically speaking, he does nothing but soil himself in public these days. There is absolutely no reason for anyone to praise anything he does.