Below is a link to two photos from the USC Digital Archives, titled "Suicide on Super Chief, 1958":
Use the photo legend to the right to shift between the images and use the sliders above the images to enlarge the photos.
While not the main subject of the of the photos, both show what appear to be refrigerator cars next to the passenger car. One is a PFE reefer and the other is a Santa Fe reefer.
While it may not be unusual for refrigerator cars to be in a passenger terminal to provide ice for passenger cars (dining service or certain air conditioning systems), I understand the Southern Pacific had its own small fleet of refrigerator cars for this purpose and SP did not rely on PFE cars.
So is this a rare exception for SP or was the car there possibly for some other purpose?