Your homebrew app, game, emulator needs to be renamed exactly how it is on unity for Aurora to be able to see & pull those certain homebrew covers etc.
So use unity to find that certain cover name & rename your homebrew title to that on your 360. As 95% of the hombrew Title, Media Identification for those apps, games, emulators, dashboards are ZERO's as these never officially released with there own title, media ID as it's a homebrew.
If Aurora is unable to see & find your certain homebrew cover after you renamed it to what unity is displaying. Only way is to manually push your covers over via Aurora Asset Editor to your 360.