The changes are excellent. Thanks.
I have used the "Next to File [Artist] - [Album].jpg" system for a long time and asked for it a couple of times. Great to see it implemented at last.
I have some cover art files in GIF format. Do they work with the new system? How about TIFF, BMP and PNG?
The URL option in the "Paste From Clipboard (Image or URL)" right-click item is a clever idea. It makes downloading cover art images from websites much easier and automatically renames the image files. Just what was needed.
Though, there is one thing that could work better. Image > Add From File starts from the previously used folder. That is useful only if all images are in the same folder. From now on it should start from the file folder or from the cover art folder depending on what is selected in the Track Images Location options.
I tested the other formats. It seems MC can use at least the mentioned GIF, TIFF, BMP and PNG formats. However, MC incorrectly changes the filename extensions to .jpg when it renames the files using the [Artist] - [Album] or "folder" rules. Internally the files continue to work after that, but of course the files should have correct names.
Also, I noticed that MC unnecessarily converts the other formats to JPG if the images are coming from the clipboard (image data or URL). It uses quite heavy compression and the resulting quality is poor in fine details. Since MC can show the other formats it should convert the images only if the image files are going to be placed inside the file tags (for compatibility reasons).
Though, perhaps the "folder.jpg" option should continue to use the JPG format and convert if necessary if that is a standard. Is it?
EDIT
"Add From File" shows by default only the files of type JPG, GIF or BMP. It could show the TIFF and PNG images too since these file formats can be used if the extension mask is passed.