To be honest, I always very much liked that photo.
It shows was is possible when people let their guard down just a little bit. Even Melania shows a rare a relaxed smile. That picture also told me that while Donald Trump was in office, he was never going to push for the indictment and/or conviction of Hillary for any of her ongoing capers.
Publicly, Donald can be very tough, but privately, he seems the type to never forget that at one time, he got along with this person. They spoke and they laughed together. Even their daughters were close friends for a long time. It would have been a heavy lift for The Donald to throw all that away, even though he would have been wiser to do so.