In my video, I use four seasons change to show the passage of time. 
Four different shapes are representing the four seasons. All four shapes start with black, then as time goes by and the seasons change, they all have their colors at the end. 

🔸 Diamond = Fall 
I use diamonds to make the starry sky cause the starry sky in autumn is the most beautiful. The stars shone like diamonds in the sky.

🌨️ Rectangle = Winter 
The rectangle fell slowly like a snowflake in the white sky.

🌸 Triangle = Spring 
Triangles can form flower shapes, so I use them to represent spring.

🔵 Circle = Summer 
After spring, dark blue and circles will appear, representing the sea and bubbles in summer.