Disneyland had been open for less than a month when this photo was taken. It looks as if the Horse Drawn Trolley is beginning its first circuit of the day, probably having just emerged from the backstage area next to the fire station. Meanwhile, patient early-bird guests watch as the Chemical Wagon is made ready for a day of old-fashioned fun.
It's no secret that Walt Disney had an apartment above the fire station. I think that this might be the only photo I own in which you can clearly see that two windows are open (although the drapes are closed for privacy). It's impossible to say for sure, but maybe Walt was up in his room when this photo was taken. He was very "hands on" when it came to his brand-new dream park, and it isn't too much of a stretch to think that he spent the night, and was getting ready to wander the premises. It's also no secret that he liked to see how guests responded to all aspects of Disneyland, looking for ways to improve the experience.