"Unknown Album" should not assume Artwork

You can let Apple know via Feedback - iTunes - Apple or make a free registration for the Apple Developer Program and then make use of Apple Bug Reporter to report the issue.

If you don't want to spend time correctly tagging new media when you add it to the library (i.e. at minimum populate Artist, Album Artist, Album, and artwork) then another approach would be to create a particular dummy track, e.g. something from the SilentCD collection, and add this artwork to it so that it shows for the other "Unknown Album" tracks.

tt2

If you want Apple to "solve" this problem, then you need to at least show that it is Apple's problem to begin with. How did the songs/albums get created or imported in the first place? If you got them directly from the iTunes Store, then I might agree with you that Apple should do something. Otherwise...

BTW, other than being a user of Apple products, I am not associated with Apple in any other way.

In general an album in iTunes is any collection of tracks with the same Album title and Album Artist, or Artist if album is blank, or that is marked as a compilation. Unknown Artist and Unknown Album (when those values are actually blank in the metadata) do sometimes get treated slightly differently, but it would be a mistake to assume they will be treated exactly the same in iTunes and on different devices. Apple is no more consistent here than most people's metadata.

tt2

If I understand your concern, I would simply name each "Unknown Album" as the song title for all the songs with no Album information:

iTunes for Windows: Edit song and CD information

Sounds like the problem is with the free tracks, not the $700 phone. If the tracks don't contain album information, how is the album art supposed to be found?