The line “Ten thousand stars I saw at a glance, tossing their heads in a sprightly dance” is a poetic description. The most accurate interpretation is:
2. The stars twinkled.🌟
The phrase "tossing their heads in a sprightly dance" suggests the twinkling motion of the stars, as they appear to flicker and shine in the night sky. The language used here is figurative and conveys the beauty and liveliness of the stars rather than a literal interpretation.