Here is the page with the Four Sons, which Zangwill notes "grow small by degrees," for no apparent reason, so it is that the the fourth son who "hath no capacity to inquire" is "represented as a dwarf." Zangwill claims that the body language of this son resembles that of a "vociferous Maggid."
He also mocked the 13 illustrations depicting all the 15 stages of the Seder, and its men with "steeple-crowned hats" and "ladies [in] sheitels." For some reason there are different numbers of people in the illustrations. Zangwill says that he's not sure if this means they were under the table:
The edition I saw was the second "thoroughly revised" edition, where some of the things he pointed out were corrected (Vienna, 1896).
Here is Israel Zangwill, by the way. Doesn't look like the sort of man who finds anything funny, so it just goes to show that you can never tell by pictures:
Here is Israel Zangwill, by the way. Doesn't look like the sort of man who finds anything funny, so it just goes to show that you can never tell by pictures: