Before I start, no one's allowed to say, "Duh, I knew that!" Because this topic has come up and I've asked the question before (well, not here. In real life.), and no one had an answer.
I've finally learned what those not-so-decorative random diamonds/blobs on old building facades are. You can see them to the right of the tree's leaves, above the windows. The very top one, over the dark horizontal border, seems to be a giant tac through a white diamond shape, while others within the bordered area have no shape at all--as if someone just hammered evenly spaced bolts to the brick.
They are ugly--but not all examples are this ugly. Some seem evenly spaced, some arc.
I hear you! You're all saying, "Duh, I knew that!" aren't you?
Well, I didn't know.
These particularly unattractive examples of earthquake safety are on 7th Street in San Pedro. I love the one on the left. I can just imagine a disgruntled engineer saying, "You want bolts? I'll give you bolts!" before going crazy on the building.
It looks like ... like mebbe giants were playing Battleship using the bricks as squares?
The author of Ancient L.A. points out that many old buildings have plastered over their bricks and these unsightly blemishes, but clearly Ye Olde San Pedro has not reached that level of gentrification. I'd like to say the bolts add character, but they're just flat-out ugly.