Apparently it was a holiday tradition in 1966ish to post cards in the yards at Princeton Place in San Luis Obispo. On the edge of one of the photos you can see the photographer using a spotlight to help fill in the dark corners of a night time photo.
Prepare to explain to future generations the concept of sending cards, stamps and post offices.
The updated version would be a giant smart phone in the yard with instant messages flashing today. Uh, oh did I just give someone a decoration idea? Sorry if the flashing lights across the street keeping you awake with crazy ring tones turns out to be your neighbor.