Currently text says, "Recommended Size: 150 x 150 Pixels..", but is actually a requirement. Please adjust the text to say, "Required Size: 150 x 150 Pixels.."

As somebody who always uploads things bigger than that, it is indeed only a recommendation. I upload bigger and it just shrinks to size on upload.

My original tries were with a 636x406, attempted over various browsers over multiple days, cleared caches, and formats. Once I modified to 150x150 it worked.

I'm guessing 600 is too big, but Ive used 200 and 300 and it worked.