First of all, kudo for this fun and educative assignment and I really enjoy it.
Just small feedback on the assignment content - in one of the UNet architecture diagram, I was confused about the dimension number beside the arrow
After some time, I realized it was the size of the image. I found it confusing because, in the lecture video, a different convention was used - that the number represents the kernel size. I think it would be more clear if the diagram was labeled as
Just my 2 cents.