Have you read the book? I came across it for the first time last week, and I’m considering purchasing it. The ebook is more affordable, but I wasn’t sure if it had diagrams, etc that would make me prefer a physical copy.
There are some nice abstract artistic illustrations at the start of each "part" of the book (and also the covers), though they are more for aesthetic decorations rather than for communicating mathematical concepts. For example, one of the illustrations is an abstract medieval-like artwork with a sun that has a human-like face, a starry sky, and a person in robes whose head is peeking through the starry sky to look at a world across the boundary. So, you won't lose out on comprehension at all by reading the ebook, but the book does have some minor artwork only tangentially related to the book's content, which might make a physical edition preferable for aesthetic/collector's purposes.
The e-version is perfectly fine, though; as the prologue states, the book was first published as part of an online column on the Mathematical Association of America's website, so the e-version appears close to the original version. The prologue writer who helped publish the book also first received the essay as a 25-page printout from an audience member at a lecture.
It was incredibly freeing for me at least to hear the message of ‘think deeply about simple things’ with the realisation I don’t care like I used to that there are other people are smarter and faster than me.
I recommend it.