[1] https://www.kickstarter.com/projects/fred/the-emoji-translat...
Written Chinese started as an image-based language.
Give emoji a few thousand years, maybe less, and it could become a proper language. I think it's already starting to evolve. The eggplant symbol has been repurposed to mean "penis". (So I've heard.)
But I think the main roadblock to the machine translator described in the article is that emoji are currently used as an adjunct to peoples' native language. Does a Japanese speaker use emoji the same way as a Russian speaker? Or German or Farsi? I suspect the answer is they don't. So trying to train an AI using texts from all these different speakers will be trying to build a Tower of Babel.
The English word "fish" on the other hand, is not a pictogram, and its evolution has not been primarily visual. Instead it has undergone evolution in pronunciation, which has indirectly affected how the written word "looks".