This is expected. The purpose of those examples is to show how an animation is produced. Yet, the way the matplotlib documentation is generated, it is currently not possible to show animated output. The images shown are the static version of the animations, i.e. the state of the figure before the animation actually starts.

One possible solution would be to not use the automatic sphinx-gallery output for those examples, but rather generate some animated gifs manually and link them statically inside the example file.

One might also opt for not showing any output (that would be easier compared to the above, but maybe equally confusing?).

The question is a bit whether either of the above is really worth the effort.

There is some hope to do something like this in sphinx-gallery: sphinx-gallery/sphinx-gallery#150

I am starting to try and figure out a workable solution to this, although I currently cannot build the docs. I keep getting this error: Warning, treated as error:
[autosummary] failed to import 'matplotlib.animation.PillowWriter': no module named matplotlib.animation.PillowWriter. Anyone know what this is due to? I have Pillow installed.

@anthonytec2 seems like you are building the docs from an environment that has an older matplotlib version in it. E.g. if you had a system-wide python with matplotlib 2.1 installed and some folder with matplotlib 2.2, then running make html to build the docs from that folder would probably result in such error.

In general I do think it's worth waiting for sphinx-gallery to sort out their new scraper system.