The kanji for ART (芸) can be visualized as an artistic performance taking place under the 'clouds' (云) in a 'field of grass' (艹). Imagine a stage set in a beautiful, grassy field with clouds drifting above, where a captivating art show is happening.
'GEI' — sounds like 'GAY' (meaning cheerful or joyful). Art and performances often bring happiness and joy to people, making them feel 'GAY'.