Even hieroglyphs should have some kind of gramma. But Emoji doesn't. That is why it is a horrible idea to use Emoji as a standalone language. It is a retrogression of civilization.

The good part of Emoji is it express some emotion which English is not good at. Chinese have many emotional decorators that are already doing so, for example, "人家就是想要那个包包嘛。" You can tell what kind of emotion is there merely by reading the words. But it is relatively not so easy in English. So Chinese tend to rely much less on Emojis than English. 

Another thing to know is that these days in Chinese, Emojis are used for the opposite emotions, which is called 阴阳怪气, and are considered impolite in a lot of situations. For example:
- 🙂️：Freaking wordless.
- 😅：Please stop being a joke, that is enough.