Or maybe a horse tied up in front of the saloon? It's 1910 when cars were uncommon and so were good roads.

The lights could be regular bulbs and the flare from a long night exposure on the slow film.

I'll see if I can download it and light blast it (not a scientific term) for details.

I'd be skeptical, but if that's not written on the card, but scratched into the negative, I'd start to be convinced.