SUMMARY
I think it'd be nice if I was able to preview annotations within the annotation tab such that when I open the annotation tab I see something like the hierarchy of chapters, and on the leaf level I see previews of the annotations I made. Maybe something like truncated texts of the annotation, whether it's an inline note, highlight, etc.

I think this feature would be beneficial because it's much more informative to know where you put the annotation relative to chapters and the preview so that you can see at a glimpse what the annotation was about, which may be helpful to the user so you can try to remember what the context was about just by looking at what you annotated without having to open the popup annotation or jumping to the page to look at the annotation and then having to switch back to the contents tab to see which chapter/section you are in.