A Transparent Water Droplet Trap

I slipped through the cracked sliding door out onto the bright tiled balcony! Chirp? Right inside a glazed terracotta planter, a miniature watering bulb made of clear glass was nestled into the dark soil. Inside, trapped sunlit water swayed back and forth. I leaned close, tilting my head to inspect the rounded bulb. Tap! My front paw touched the cool, smooth glass. A single giant bubble glided upward through the neck with a tiny, echoing glug! I hopped back in surprise, tail twitching, then crouched low to watch the refracted green garden miniature upside-down inside the sphere.