My coop for standard/LFs has a skylight. I adore it and many of the chickens appear to like it, as they like to roost up near the skylight whenever possible. The cochins, however, cannot perch up there given their weight.
My bantam barn has 4 windows and while they do the coop bright with sunshine, its also created some odd situations. Our little Sizzle cockerel likes to eye us all via the windows and screech at Big Blue, the cochin rooster (who is allowed to free range). He's gone crazy attacking the windows trying to get to Big Blue. He doesn't do this when in his pen, just the coop.
While the whole thing is crazy and humorous on some level, its also a bit alarming. Reconsidering the window design, I'd have put them higher up or just gone with skylights so he cannot see the other chickens.
Also, whenever the security lights pop on due to movement, the bantam cockerel crows at all hours of the night! That's likely a placement issue, but considering the chickens' reaction to sunlight or any light that may come in those windows is something you need to plan for.