He’s a mad scientist dude. They do that.
Einstein was eccentric and awesome. That’s just how he rolled, man.
As far as I know. He only did it the once. It is just a very popular picture of him. It shows the lighter side of a heavy dude.
It was a publicity shot taken after his theory of relativity was accepted as scientific possibility ,upto that point every reputable scientist swore by Newton`s theories.Einstein disproved the main ones and so in the pictures he is telling those scientists just what he thought of their outdated beliefs.
hehe thats how my man albert rolls 😀
haha he was a fun and crazy guy