Thank you muchly.

A remix is basically a rewriting of someone else's story. The plot and the pairing stay the same, but everything else is up to the remixer. They might change the setting or the point of view or something else, while still keeping it recognizable as a link to or a deepening of the original story. If you read roga's original, you can see some of the same lines, for instance. If you're interested in the process, I wrote a commentary for this one here.