First of all, you need to check whether you're using the old Google Chat or the new Hangouts. They look a little different and have different features:
In Hangouts, you can use way more emoji (!) and send pictures or draw doodles (but for those last two, you need to have a Google+ account):
If you want to keep using the old GChat, you can enable pictures in messages by navigating to your Gmail settings, then going to the "Labs" tab:
Also in the Labs tab, you'll find an option to float your Gchat contacts on the right side of your screen:
You can translate your messages into a bunch of different languages using Google's chat bots:
See the full list of bots here.