The title of this poem establishes the alternate reality right from the start. As soon as we read the title, we know we're dealing with the figurative, or metaphorical, in this poem, and not the nitty-gritty real world. But the cool part about this alternate version of reality is how it can change the way we think about the real world, too.
I'm a riddle in nine syllables, (1)
This line continues the warning of the title—don't take me as real, it suggests, I'm a riddle. Yet it doesn't say "just" a riddle. This poem, despite masking what it's really talking about through metaphors, still has something to say about the real world.
A melon strolling on two tendrils. (3)
Here's an example of what the metaphorical world of the poem looks like. This poem is in a world where melons can stroll on top of two tendrils, or vines. Fruit and plants can take on human characteristics. Yet, remember, this fruit is actually just being used to make us think of pregnant women in a different way. This leaves us to wonder if it's the melon who's become personified, or the person who's become fruit-ified.