The poem is only three lines long, but it holds two very different moments side by side. In the first, the speaker has a strong poker hand, one with a king in it. In the second, the speaker is throwing up. The dash after "king" and the line break that follows make the shift feel sudden, almost like a stumble.
What's striking is the speaker's reaction. Instead of focusing on the sickness, they "look for good cards," as if the next hand might fix things. That could be a gambler's stubborn hope, or a way of pushing through feeling awful by staying in the game. The title, "Royal flush," promises the best hand in poker, but the poem never says the speaker gets it. That gap between the title and the body leaves a quiet irony.
The mood is wry and a little grim. There's dark humor in treating a bad moment as just another turn of the cards, and a hint of vulnerability underneath, since the speaker seems to be hoping for luck while feeling unwell.