What's provided currently at [1] doesn't provide the reader with any impression of the teaching style or quality/quantity of visual aids.

I'm very likely to buy a hard copy of such a book, but not unless I can do the equivalent of flipping through it like I would in a book store.

Consider changing the preview instead to a scattered sampling of some of your proudest pages.

[1] https://pimbook.org/pdf/pim_first_pages.pdf