MP3 Album Art file location ?

I have a USB flash drive with MP3 files that displayed album art when played in my old car but does not show the images when played in my new/used car.

Did some searching & it looks like the artwork may need to be embedded in each mp3 file. It’s been years since I worked with the Mp3tag app but it appears my artwork is stored separately but in the same folder with the mp3 files, at least from what I can figure out..

I have duplicate files on my PC & want to use that to hopefully modify my mp3 files. Using the PC I open a music folder using Mp3tag & it shows 17 songs. As I click on each song it displays the proper image.

Then I use File Explorer set to show hidden system files and it lists the 17 songs plus AlbumArtSmall.jpg and Folder.jpg. AlbumArtSmall.jpg shows a 75 x 75 pixel image & Folder.jpg shows the same image with 200 x 200 pixels. FWIW that image is the album art from the last song in the folder.

Where is the album art hidden for the other 16 songs?