Why does qq speak as an expression, and when it goes out, it becomes a text?

In fact, qq emoticons are a combination of some English letters and symbols (the earliest smile code is /smile, and when you directly input/send a smile in the chat box, it is a smile expression. Later, the smile code became /wx, and now it has nothing to do with the word smile). After qq chat box detects these expressions, it will replace them with some intuitive pictures, which are the expressions we see. Lz's expression is the code that the other party sees, so it should be that the other party's qq can't automatically replace these codes with expressions. It should be that the qq expression pack version is too low or the qq version is too low.