The Statue - S7-E23
Continuity mistake: At the end, when Aunt Bee concludes the reading of the minutes and mentions the improvement fund, she's holding the blue folder up in her hands with its notepapers inside, but in the next shot one of the notepapers is suddenly flipped over the top of the folder. (00:23:45)
Answer: Those "boxes" are valences that used to be very common, before air conditioning. They allow for windows to be open during rain storms. They permit air circulation, without letting the rain in.