The images are cropped a bit differently, but I think they're the same images...slightly tweaked

On the black & white photo there is a motorcycle in the lower left corner, in front of a row of six parked cars.
On the postcard there are the same six parked cars, but no motorcycle.

The black & white photo has a person crossing the street, in the center of the photo.
The postcard doesn't have the person crossing the street.

The black & white has a scaffold, or something, blocking part of the Las Vegas Club sign.
The entire sign is visible on the postcard.

You might think that the 2 images were taken a few minutes apart...BUT...in the lower right corner is a person wearing a cowboy hat. And he's in both photos.

There may be other differences, too...