Static album cover art is more nebulous in the streaming age. What's interesting is the different approaches users and musical groups have taken to accompanying video on platforms like YouTube. There is not yet a de facto standard to replace the static square image of yesteryear, but there are a lot of interesting one-offs.
However, it still feels very limited. They're all looping cinegraphs, they don't 'do' anything.
For an example of a genuinely imaginative liner notes experience, check out the floppy disk that came with Billy Idol's ambitious 1993 effort "Cyberpunk": https://www.youtube.com/watch?v=Mjl6As2lRGU
