The BOOK is large (Well over 1 M of a large novel). The file SIZES are all nicely sized for a portable reader using ADE
Personally, I find the ridiculously long filenames insane to work with (the names require that the file browser use 30% of the screen space to show.). Besides they have SPACES in them. The current filename conveys no useful information. Bulk rename them!
Sigil will display an image file in a seperate Tab (you probably know that).
Right-click the Image within the book (where it is being used) allows Lots of options. Open in Tab being the way around the preview box size
Developers: Could we have a few simple Image controls here like Rotate Right/left, Flip , and the one I really would like: Wrap in SVG (Like Calibre does with the Cover)