I am not an academician or a teacher, even then I fail to understand on how Photoshop can be a theory subject?. It seems it is so in some schools in Chennai (may be in other schools across India) for students of VII standard. See the below notebook of a Class VII student who has written about Photoshop “Brush” and selecting Colours from the textbook. When I saw my niece having a textbook on Photoshop I was curious and on examining it turns out they teach in class “Photoshop” as a theory subject and are expected to answer exams on the same.
I may be biased here, as I didn’t have any formal computer science education and my engineering discipline was Electronics & Communication and all my computer learning has been practical and self-taught.