In addition to the problem of a lack of pictographic standardization, there is also the issue of a lack of dictionary definition standardization for each symbol. It's one thing to describe what a pictogram is a picture of, and another thing to interpret a verb/noun/adjective/etc definition of the pictogram.

On the other hand, I would expect all written languages to have an infancy where the details of all of that get hashed out. For instance, there is http://emojidictionary.emojifoundation.com/ which is trying to solve the latter problem.

Emoji still looks to me like a toy rather than an actual language. It lacks many of the traits that a real communicative language requires (verb tenses, articles, etc.) Maybe someday it will evolve and grow into that.