Bracket is for a handlebar bag. If I don't need the panniers or I need access to things (e.g., cellphone or camera) during a ride I'll pop my handlebar bag on.
If I think of it, I'll photograph my commute next week. Can normally see the mountains really well in the morning and sunset in the evening this time of year. It's a funny commute. I live and work on the left bank of the Tennessee River, but get down to River level one additional time. In between I pop up onto the limestone karst plain. So it's up down up down to work, unless I take a longer route.