I'm guessing that's the work of the animated-block-trick-thing, right?
Not only can you add animations just by adding more images down vertically, but you can customize the order and duration of frames through use of a .txt file for each texture. They customized the timing on the textures so it works as a clock. The downside, as someone pointed out, is that this is reset from reloading, rejoining, etc. The upside is, if you don't rely on a huge system, this is effective enough.