submarine
Explanation
The Joke
A child excitedly announces "Mama! I'm drawing a submarine!" and proceeds to describe all its features: "Here's the kitchen and here's the dining room and here's where the toy cars are and here's where the gardens are..." The mother points out that what the child is describing sounds exactly like their home. The child responds: "Boy, you'd think you'd be at home, but you don't use it. It never feels like home. It's almost as though you aren't a submarine mama."
Later, at bedtime, the child tells the mother "I think it's wonder woman" and she replies "Honey, wonder woman died." The child seems to be processing thoughts about what a submarine "mama" would be like -- essentially suggesting the mother does not inhabit her own home fully, a strangely perceptive and cutting observation delivered with childlike innocence. The bedtime coda adds another layer of the child's stream-of-consciousness tangents that land with unexpected emotional weight.
The Humor
The humor operates through the familiar SMBC device of a child saying something that sounds innocent but carries an unexpectedly sharp or philosophical edge. The child's submarine drawing is really just a drawing of their house, which is cute and normal -- kids often draw what they know. But the child's observation that the mother doesn't really feel "at home" in her own home, delivered through the metaphor of not being a "submarine mama," transforms a silly kid moment into something more poignant. The bedtime scene adds a surreal non-sequitur that reinforces the comic's tone of children saying bewildering things that parents must simply absorb.