Almost certainly a hand colored photograph. Although
color photography was done even before 1905 it was
difficult. Most often it was done by making three color
separation plates. There were special backs for cameras
allowing fairly rapid chaging of the plates and filters but
photography of anything with motion was impossible with some
sign of the motion.
 A great many postcards were printed by adding color to B&W
photos. You will find many of these on the Los Angeles
Public Library site by searching for hotels or other
landmarks. Try searching the photo data base for Westlake
Park for instance. Most often the original photo is also
there with the card made from it. Of course, its hard to
know now but I think most of the colors were authentic,
i.e., are the right color, although they are often
exagerated. The eBay card, above, looks faded but was
probably originally quite vivid.

Oops. . .the seller removed the image.
You can find it here:

http://www.lukejtornatzky.com/misc/graphics/trolley_1910s.jpg

-Mark