I love it when great shows crosses the boundaries of it's setup and in some episodes just freaks out. Some examples are Buffy the Vampire slayer when in one episode it becomes a musical or when a Farscape episode is an animated cartoon.
Glow just did the same here. Suddenly we have stepped out of the drama and we are instead treated to a GLOW show and how it could have looked when aired. This episode was a great way of showing the result on what Sam Silvia promised in the last episode "we will die on our own terms"