In the previous post Sally is wearing a Heart Guard reminder sticker on her head. I sometimes put these on the dogs heads because we administer the medicine (or special treats as they are known) to all the dogs at once which means I really only need one sticker for the calendar.
Penny does not appreciate it when Luke and Sally try to embellish their wardrobes with any accessories and will attack them in a way that says "get that off now!" Penny understands that dressing up dogs is terrible (but dressing up AS a dog is adorable), but she's not content to leave it at silly costumes, collars are fair game as well and Luke usually loses his in the yard once a month.
So here is a picture of Penny attacking Sally's collar because she has noticed the sticker on Sally's head. Penny does not realize, however, that she too is wearing a stupid accessory.