This looks _really_ familiar. Will see if I can find a copy and verify! (Will also post the seal if I find it.)
UPDATE: So I found the book on Internet Archive [0] and I really think it's the real thing. Only caveat: no seal. There's a whole section on creating animated GIFs (which I recall the book I had having), but the example to create a GIF is not a seal bouncing a ball but rather just a bouncing ball sans seal (pg. 261). I'm pretty sure the seal was a false memory at this point.
I've thought of this book often, and I'm thankful to you for sending this my way. I'm 99% sure it's the book given the page count, cover, chapters, and year it was published. Even if it isn't though, it's a wonderful example of the sorts of references at the time.
Sadly, I think it was a partial false memory. There is indeed a section on making animated GIFs, but instead of a seal bouncing a ball, it's just a bouncing ball sans seal.
Here's a screenshot from the book (it's on Archive.org)
