when i was thinking about it i kind of had the idea light = happy mood, casual attire, daylight; and dark = moody, angry, wild attire. Talking with my friend about the idea i told her that the day shots i was thinking downtown, nicollet mall, business-casual outfit, and a cheerful feeling. For the evening shots i said the outfit was all up to you, and trying to convey the opposite of what was previously shot. And during the class critique the 'dark' shots were more popluar. the day came out looking like a standard portrait, with the exception of maybe the last shot by the church where part of the wall blocked the flash and i ended up with a drop-shadow outline.
I didn't do much editing to these photos other then maybe changing the white balance in photoshop post-production.