Not much later, when I linked someone else who had seen both of those images to a painting by Rembrandt van Rijn of Europa, she said she was looking for my fishy in it. So I decided to take the initiative and I made a quick manipulation of the picture.
Then I suddenly realised it could work quite well as a meme. In case you’re interested, I saved what I used in the painting as a transparent PNG. So if you’re interested in making my fishy into a meme, I doubt it could get any easier.