1. Small faces worked (“much smaller than life-sized”). I found that life-size faces produced the biggest effect. I never studied the effect of face size in detail (trying many different sizes). I first experienced the effect after watching Jay Leno do his monologue on a 20-inch TV — much smaller than a life-size face. Obviously we recognize faces when they are much smaller than life-size. For example, we recognize faces in newspaper photos. And we recognize people at a wide range of distances, meaning that the retinal image of a face can vary greatly in size without preventing recognition. Both facts suggest that the size of the face may not matter a lot for this effect.
2. He watched right after he got up. There is surely a window of effectiveness — a time period outside of which the faces do nothing — but when? And how long? I don’t know. It surely depends on your exposure to sunlight, which is incredibly hard to measure. Navanit found a simple rule that worked (“watch right after you get up”). When I first experienced the effect I did the same thing that works for him — I watched TV a few minutes after I woke up.
3. He became less irritable (“much more emotionally resilient to irritants and bad news”). I noticed the same thing. A paradox of depression is that people become more irritable. Depression is a disease of passivity — you don’t want to do anything — but irritability is over-reaction. I’ve heard it claimed that depression may be caused by not eating enough fruits and vegetables. Okay, lack of a vital nutrient might cause people to have less energy, but why would it make them more irritable? Not obvious. The fact that the morning-faces effect includes this component is part of why I think it sheds light on what causes depression. Perhaps anything that raises your mood will make you less irritable but I can only say it didn’t feel that way — it felt like something special. Like everyone else I have my mood raised by ordinary events (e.g., good news, a joke) and these do not seem to produce a big increase in serenity.