"Initially, we looked at common static image formats such as PNG sequences and GIFs, as well as even more compressed formats like WebP. It quickly became clear that these wouldn't work without drastically simplifying the animations for file size, and that we'd have to accept the drawback of static images not scaling up or down very well."

So, reading between the lines, they've made what they think is a better GIF. And perhaps it is, and if so, that's big business[1], and so having a first-mover advantage on mobile could be highly profitable. (They're a public A-corporation, after all.)

But who knows; I could be reading too far into it or just flat-out wrong, too!

[1] http://www.popularmechanics.com/technology/a21457/the-gif-is...