On Hollywood Boulevard is a camera shop with a unique theme that serves to distinct purposes of why it's at Disney's Hollywood Studios. The store does actually sell what it's exterior depicts, cameras and film and related items (usually the outside doesn't have relevance to the merchandise found within) and sports an exterior that is a larger-than-life camera.
Some may recognize the exterior as the Darkroom is a nearly identical copy of a famous Hollywood landmark. It's based on a store with the same name that was located at 5370 Wilshire Boulevard, Los Angeles. The exterior is that of a 35mm camera and in both the Disney and real life versions, you'll find just that. One minor difference with the Disney version is it's addition of Kodak name to incorporate the corporate agreement the two share. This important Hollywood landmark made an impression on the Disney Imagineers and the building's exterior found its way into the theme park.
The Darkroom also is at the Studios because it's a classic example of "California Crazy" architecture. Like Dinosaur Gertie, the Darkroom uses larger than life depictions in the exterior to bring attention to the store with the desired result of making more sales. This architectual movement was popular in the 1930s and in California predominantly. Since Hollywood and Sunset Boulevards are supposed to be reminiscent of the Hollywood of the 1930s and 40s, it makes perfect sense for this architectual style to be represented.