I've always assumed that it was either to get one's attention, or to be viewed in a rear view mirror, which seems kind of dangerous, when you think about it.

But I don't know for sure. I would be crucified at AskMe for this vague answer.

I like the reverse paint transfer answer. It just doesn't seem plausible that someone would have tried a trick like that to catch the eye. Usually such things fall into larger trends, and this would be the first instance of it I've ever seen. Is it in the parking lot behind the Lotus?

Yeah, I'm wondering if they weren't initially painted, but the signs were instead transferred on to the wall, almost screened on somehow? Some technology of the ancients that we have forgotten? Possibly some kind of vinyl that was applied directly to the wall with really strong adhesive. Some adhesives & spray polyurethane kind of things can eat away backing and leave ink, or vice versa. Then as the top slowly wore away or was painted over, the back or mirror image was left underneath.

iconomy, none of the other answerers on AskMe have a clue either. Everyone's just fishing around the maybes.

I think the most likely explanation is that this building was swapped with it's bizarro-world analogue during a fight between Superman and Bizarro Superman.

pieisexactlythree: No, Coca-Cola sign is on SE Grand, right in the shadow of the Hawthorne bridge (or maybe it's the Morrison bridge...one of the two), in the parking lot of some social service agency.

I'm quite positive that it wasn't to catch the eye in a rearview mirror, but maybe it was some weird transfer from some old adhesive-like sign.

A couple of thoughts: The "relieves fatigue/sold everywhere" slogan dates from 1907/1908, and the sign is painted low down, which strikes me as unusual. I think they are more often found placed higher up for greater visibility (like here or here)...

So my theory is that this building faced something like a department store or general store, that had big glass "window-shopping" shop windows, that weren't so common before that time (I think sheet glass only started being made in the early 1900s), and that the sign was designed to be viewed as reflections by all the street level pedestrians hanging about to look in the fancy newfangled big windows. I mean, the large shop windows may have been such a novelty that some advertising was specifically designed to exploit their attraction.

I'm going with Wild Eep on this one. It may have been so that people could see it reflected off the windows in the building opposite. I look out the window, I see "Coca-Cola" in the windows opposite. Especially if it was originally in a fairly narrow alley where ground-level people couldn't be expected to see it. Cram an ad in wherever there's room!

Or, it could've been done by cheap immigrant labor that didn't know they had the stencil backwards. Freakin' immagrints. Always doing stuff cheap. Morans.

cmonkey--I thought someone with an interest in the advertising history of the brand might know something, so I sent an e-mail to a Coca Cola collectors group. If they answer me, I'll let you know.