Streams.
These are communities that you post in, sort of like subreddits. The default stream is the fun stream, but there are many more of them including ones you can make yourself.
Points.
You can get points either by upvoting other people’s memes, or get upvotes on your own memes/comments. If you reach a certain amount of points, you don’t have a timer on commenting on a specific image, you can make your own tagline, and you can post on streams that require 10,000 points and 30 days experience. You also unlock icons with said points.
Meme making tools.
You can use either existing meme templates, or you can make your own. You can even publicly upload your own meme templates. You can add text, adjust text, add images, and draw over images. Of course, with gif templates, there are a lot more tools at your disposal.