I wasn't expecting this to be tacked on to the end of "The Sealed Card", but it was a nice surprise. It's basically a little animation expo and experiment, showing a story from Kero's point of view. Suitably, the animation is top-notch, not just from an "it looks like they did more frames" perspective, but from a "there's some remarkably good composition here" one. The sword-fight, the drain pipe, the chase after the bouncy-ball takoyaki, the reveal of the octopus piece. Just the choice to show the human characters at low angles in general.
I also appreciated the chance to see a bit more of Spinel. I never thought Eriol's familiars got enough screentime to be full characters in the main series.
This is a great short.