Today’s Bizarro, with more puns:
The second pun turns on word division (compare ice cream vs. I scream), with the extra twist that the indefinite article a(n) is usually attached to the following word and pronounced as a unit with it — so than the [n] of an is usually syllabified with the following word, making an ice and a nice phonetically identical.
The third plays on the convention of using obscenicons to represent swearwords.
Of course, all three depend on cultural knowledge: among other things, that Brussels is in Belgium, that Brussels sprouts are a vegetable, that the man in the first panel is planting something, and that the scene and his costume suggest Belgium (what makes it preposterous is that he’s planting pig snouts); that the costumes and dwellings in the second panel are appropriate for Eskimos and that Eskimos live in cold, snowy climates; and that Men’s Wearhouse (itself a pun) is the name of a men’s clothing store.