The article said he made "some junior designer mistakes". If Sid talked to him about what those specific mistakes were, and tried to identify what attitudes/mi

The article said he made "some junior designer mistakes". If Sid talked to him about what those specific mistakes were, and tried to identify what attitudes/misunderstandings/inexperience/lack of skill caused him to make those mistakes, and how, specifically, Sid avoided them, this would be an incredibly vivid learning experience; and a deeply motivating experience for someone who wanted to improve. It's an ideal opportunity to develop talent. It's true that Sid probably doesn't fully understand his own approach, and even if he did, there's a junior designer would be able to absorb and adopt it all instantly. However, Sid would have some understanding, and the junior designer would be able to absorb and start adopting some of it; and simply having a kind and encouraging word from Sid would count for a lot. If Sid didn't go to the trouble of doing this, or if the junior designer expected to be great without practice, it would indeed be demotivating.