Karen O and Danger Mouse’s album collaboration is fantastic not because the songs are engaging (which they are) or for good lyrics (all together haunting, energetic and hypnotizing), but because the album seemingly breaks all the rules.
In the past, artists could hide behind the shield of a stage-name, a wig or an eye-catching outfit. However, in the digital age it is becoming more and more difficult for anyone –– celebrity or regular Joe –– to maintain privacy.
To answer the question, good album art is iconic, a symbol of the music, the artist, and the era of hip hop that it falls in. Good album art is beautiful, drawn by artists with a vision, or photographed with care. But most importantly, it captures the essence of the album. Music is an experience, and the cover is a part of that experience.