I don’t know.  If I don’t have time to review a hot post I don’t have time for I screen shot it, and come back to it.

I suppose the algorithm just tried to give you new feed to look at, in lieu of the same content again. 

 That's a good idea but sometimes you didn't realize you wanted to find it again and no screenshot  

 True.  But X doesn’t know.. it tries to give you slightly different feed so you have more choices.