"An RCA Victor Recording Session"

On two separate occasions, I've come across an unusual early white label RCA Victor 45 titled "An RCA Victor Recording Session", both sides featuring highlights of Fran Warren recording "Stormy Weather". I think the catalog number of this is simply "RS-1". What was the purpose of this record? One copy I have was found among a collection of early commercial 45s from roughly the same time frame (1949-1950), so I have reason to believe it was some sort of premium.