"If Randall spent, on average, one hour drawing each frame, it would take him 9.375 days of constant, nonstop work to finish this. If he instead spent an average of 10 minutes per frame, it would take ~37.5 hours, or almost an entire 40-hour work week."

This statement is a bit flawed since he doesn't differentiate between almost empty frames and frames with much detail. It obviously took longer to create frames with a lot of details than empty frames or frames with little detail.

Still, it's an interesting post. Randall clearly put a lot of time and effort into creating the "Click and drag" world.