I’ve just watched the video for Lesson 20, and I like the analogy you made between doors, balconies, etc. Also, I appreciate all the additional information/examples you add. All of them are very helpful.
To do the activities/challenges, I had to look at Suz’s image, like you showed. I tried first with the PSP layers, but I was getting lost along the process… I, too, used the history palette to confirm whether or not I was right in my answers.
I will check later this new challenge for Lesson 16! 🙂