Case in point when it comes to similar content issues...

The image below was initially rejected for similar content. And rightfully so, when one considers that the search for elephants yielded over 1 and a half million results for elephants. So I fussed around with keywords and put keywords related to elephants near the bottom of my list, and keywords like spirals, fibonacci, surreal, unique, unusual, funny, etc. to the top of my list, and it was accepted. Thus, further suggesting that similar content rejections are based on keywords and even the order of same.

Surreal Elephant with a Long Trunk.jpg