One remarkable thing about Indian Summer is how thick references are in it, such as posters for Shana, Dokuro-chan, etc. Normally anime does not go so far, or focuses on properties of the specific studio, but this is just insanity. If you thought Lucky Star was bad, watch this.

So, at some point they hold a robot maid competition, and Muriel, Mahoro, Multi, and a few other characters I do not recognize all take a part... with Nanoha among them (who is not a robot in her own show).

OOPS: Hold on a moment, Muriel wasn't a robot either. So I misunderstood what they were saying and it's a generic maid competition then, open to humans. It still doesn't explain what Nanoha is doing in it.