This is a fair question. No other president was ever reported on so extensively about his mood.
On the other hand, no other president has been so moody and impulsive. Every presidency has reporters asking how the President comes to his decisions. For prior presidents, there were reports about the president's close advisers or experts the president speaks to, or a look at the articles or books he reads. But Trump doesn't seek the advice of experts, and he doesn't read. The source of his decision-making seems to be: his mood, what he sees on Fox, and whatever person last spoke to him, in that order. Given that, and the fact that in the leakiest presidential administration in history which means plenty of people are willing to give anonymous quotes about the President's rage-tantrums, it is both fair and inevitable that reports of the President's mood have become a staple of the Trump presidency.
On the other hand, no other president has been so moody and impulsive. Every presidency has reporters asking how the President comes to his decisions. For prior presidents, there were reports about the president's close advisers or experts the president speaks to, or a look at the articles or books he reads. But Trump doesn't seek the advice of experts, and he doesn't read. The source of his decision-making seems to be: his mood, what he sees on Fox, and whatever person last spoke to him, in that order. Given that, and the fact that in the leakiest presidential administration in history which means plenty of people are willing to give anonymous quotes about the President's rage-tantrums, it is both fair and inevitable that reports of the President's mood have become a staple of the Trump presidency.