Yes, as do music video's and performance visuals.
Being an artist menas you're the full package, not just another singer.
Your visuals need to be the glue that makes the complete era a whole and gives a cohesion so the public remembers the distinctiveness of that particular release, although popstars don't realise this enough.
OT: I do think people (particularly on this site) change artists their vision like album covers and album tracklists way too much though. Like those tacky coverlandia things being made in 2 minutes over the original just cause it's 'different'.