Looks like you only have the one backup.
If you want to keep a baseline or other specific backup image, rename it slightly to windowsimagebackup.old or something like that. Then you can save a fresh image without overwriting it. It has to be renamed to its correct name and placed in the root of the drive to be detected during reimaging.
We have so many questions about multiple backups not being saved correctly that I don't think it can be counted on otherwise, unless someone knows the solution.