Did you know that the default behavior of the web is to play .gif files automatically if they are added to websites? Did you also know that this is an accessibility issue and disruptive to those prone to motion sickness and other visual imparements? It's also an odd default but unfortunately because of how the web was built, it's one of the few default accessibility issues that exists.
HAX automatically handles GIF files and ensures that they are NOT played by default. It does this by taking a screen shot of the gif (or allowing you to supply one) and then creating an interaction where the user has to click Play on the GIF in order to see it playing. This is a great example of the simple ways that HAX can improve the default accessibility of the web by eliminating the ability for users to cause an accessibility issue in the first place!