As the special itself calls it, this is episode 25 of the show. A better name would have probably have been: Kill la Kill Epilogue.
After all the chaos of the main story, our protagonists have to finally graduate from Honnouji Academy, and this graduation is both literal and metaphorical. The theme of the episode is about graduating as in, moving forward with life. Moving forward while remembering the past and using what happened as lessons to bettering oneself. About how graduating from the uniforms that we had to wear is normal and has to happen.
The Art/Animation/VA/Direction is all the same as the main show, so I won't bore you with stuff you know.
This episode puts the cherry on top of the amazing cake that Kill la Kill was, if you loved the cake, you should really make sure to finish all of it.