The wall around this window was thickened during construction when it was realized the crown above the refrigerator would not land on the wall. To compensate for the already ordered window not being designed for the thicker wall, the area below the window was treated with panels to achieve an attractive inset look for the window and the area below it.
The HVAC vent above the cabinet to the left of the door is an extra kitchen supply we put in all of our kitchens. Kitchens often get hot in the summer when owners are cooking, so we add an extra vent up high to supply cool air (versus the normal first floor supply vents which are in the floor).