XOWA can download images from either an internet wiki site or a local tarball. In both cases, the folder structure has a specific layout. For example, the A.png file would be in the following hierarchy "/root/7/70/A.png"
A request was made for XOWA to be able to read images from a single directory. Using the above example, this would be "/root/A.png"
This requires non-trivial changes to the code. It may be implemented whenever the thumbnails initiative is completed.