Here are two views of the Tomorrowland Skyway building, both were likely taken from the Disneyland and Santa Fe Railroad. This first photo is from a bright sunny day in October, 1958. The colorful shapes on this building are fun, in a way they are reminiscent of the much more playful and fanciful "Tower of the Four Winds" that Rolly Crump designed for the 1964 New York World's Fair (though Rolly didn't join WED until 1959). There are a few attraction posters visible...in those days the posters were obviously used to add color and fun to areas that were not especially attractive to the eye (light poles, walls, etc).
This second image is from an undated slide, but there is the Matterhorn, so we know that it is from 1959 or later.