In addition to owning a few of the albums pictured, I had seen some of those covers before in a book my wife gave to me that's a collection of Blue Note album covers. But the Retronaut piece covers a much wider range of albums, including some really obscure ones.
I thought I had a pretty broad knowledge of jazz trivia, but I learned some things from these pictures. For example, I knew that Ralph Sharon was Tony Bennett's longtime accompanist, but didn't know that in addition to making records with the Ralph Sharon Trio, Sharon had at least one solo album, too.
The story points out that despite media limitations that you wouldn't even think of today, jazz album cover art (and particularly the Blue Note covers) was very innovative and forward-looking. Some of them, however, are fun just because they capture images of a bygone era, Here's one of my favorites, the cover of Home Cookin' by The Incredible Jimmy Smith.