partly cloudy references the German idiom "Mir scheint die Sonne aus dem Arsch!", literally "the sun shines from my ass!". Often used with biting irony, it mocks a state of exaggerated optimism or forced cheerfulness in the face of reality.
By placing this bright, joyful sun into an otherwise grey, rainy scene, the piece highlights the emotional dissonance between inner truth and outward appearance. It becomes a mediation on performative happiness - on how society of demands sunshine, even in the midst of storms.