Click the flag and some random numbers will be generated. Click the cat and the "Bubble Sort" block will activate. Bubble Sort will replace most/all of the numbers in the list with blanks instead of ACTUALLY SORTING THEM. (The remaining numbers would be at the bottom of the list.) Look inside and you will see.
The Bubble Sort tutorials on YouTube are edited and clickbait. Let me know in the comments if I did something wrong in the code.