I was trying to find a higher resolution copy of this photo, and came across what looks like the original photo, without the "Watch The Fords Go By" banner. Does it look like the same photo as the Ford banner pic? I did a little checking, and it appears one of the firms that were members of the Adcraft Club were working (advertising) for Ford.
I believe this is the earliest use of the slogan "Watch the Fords Go By". The slogan was used at least into the 40's.
If it is "doctored", it looks pretty good. Maybe the photo with banner added was in exchange for the use of the cars?
What appears to be the original photograph, appearing in a June 1907 "Automobile" magazine:
Seems to me you can make out the two poles holding the "missing" banner in the bottom pic.
Ye Olden Photo Shop .....
I agree the Gary Schreiber -
The photo without the banner is the one that has been doctored.
Eric is right, the lower picture has been doctored but so has the upper picture.
The lower picture has a blurry window on the building and there is a rather prominent change in the lower part of the trees. As Gary Schreiber states, the poles are there but the banner has been painted out and the lighter part of the trees and the window in the center building has been added.
In the upper picture the words are all in a perfect row. The letters in a fabric banner would not align in a perfect row. Well done for retouching done over 100 years ago.
One can assume that the original message was other than "There's a Ford in your future" because I do believe that as Rob Heyen stated that message was initiated in the late 1940's perhaps with the 1949 models. I remember their advertising with a family and one boy and one girl. That was when Ford stopped the transverse springing and added Hotchkiss rear axle and finally got rid of the torque tube drive.
I think your right about the "non Ford" photo being altered.
It almost looks as if the area where the sign "was" has been shaded in a little differently (hard to tell with this resolution).
Possibly the magazine needed an advertising free photo for the article.
Reference the use of "Watch the Fords Go By", the slogan first appeared early in 1907. This late June Ford ad uses it toward the bottom of an advertisement about the 24 hour endurance record.
And an "eye catching" one from the late 30's: