The options affecting the image are all only on the right click menu.
This makes editing the image and associated fields rather more cumbersome than operations on the text fields.
Similar to how I can edit the audio by double-clicking on the icon on the left of the file list and have MP3DirectCut open on it, I would like to be able to choose a tool action for double-click on the image (which now does nothing) to open IrfanView, PhotoShop, or whatever on the image. Obviously this would require the image to be extracted to a temp file, and then on the app closing, replace the image (after confirmation) in the MP3.
If you use Adobe Acrobat this allows you to edit embedded images in that way.
There is a cut/copy/paste option on right click of the image. So all that's really needed is to make "double click" on the image have an action configurable on the "Tool" options.
e.g., "Copy" image to clipboard, Open selected tool, then maybe "Paste" if the tool accepts that.
Or save the image to a temp file and have a command line to open it.
Text fields associated with the image are only accessible by right-click on the image, and not directly editable. (Cover description, Cover type.) Can these have text boxes displayed below the image like the other text tags?
Also the display of the image in MP3tag is rather small. Can the display size of the image be an option? Or configurable to zoom the image, say on a single left click? Or ideally, just be able to drag a corner of the image to make it an arbitrary size. Since quite a lot of images seem to be 500x500 it would be nice to be able to see at least that size.