There are tricks to get it.
It uses the fairly standard media player process. If you have your music filed by folder then you can add a jpeg with the dimensions of no greater than 500x500 and call it cover.jpg. That way it shows the cover for the album. You use Google image search to find the album cover. You can downsize to 500x500. You can also use clip software to grab the image and resize.
This technique is useful if you haven't got embedded art in the music file, flac or mp3 etc. With embedded art it needs to be in the 500x500 size if not it can cause strange things to happen like the unit rebooting. That was last week's
problem for me. I covered it on this thread:
HI Just got a 2021
Cupra Ateca, C&S happy with it so far, bit different from my Scirocco R, certainly has a few more toys, one thing I can not seem to work out is
how to play music files, On the Scirocco I just put them on a sd, put them in the slot and it played easily, Is there a SD or USB...
www.seatcupra.net
This was a rogue embedded cover but using mp3tag I deleted the embedded one and used the external cover.jpg one. People with large mp3 collections using mib2 standard units use those tagging programs to adjust the covers. I have my collection in flac and use the external directory cover method, but as said a rogue Flac file had an embedded one that blew the system up to crash it. Took a time to identify the issue. A few days of testing permutations but always the same new tracks put on the SD card . Examination in mp3tag showed the embedded one on the file was pretty large, 1,500 × 1,500. I found a VW thread of people moaning about strange behaviour on their mib2 standard units, same as these but different firmware. Keep with in the cover jpeg limit and the limits to numbers of tracks and albums and you are fine.
Fiddling with embedded art can be done with this software:
Mp3tag is a powerful and easy-to-use tool to edit metadata of audio files.
www.mp3tag.de
For most media players you don't need the embedded art so you generally don't bother with it if your music is filed by album, if it's assorted you might or have a rogue large jpeg embedded then it's a job for these tag editors.