Pete Smith worked for the shorts division of MGM and often narrated how-to films. Well, I cannot stand the guy's narration, as it comes off as very self-satisfied...and annoying. Smith makes jokes, most of which fall completely flat and the notion of less being more never occurred to the guy! Because he narrates this short, it clearly knocks off a few points...especially when he speaks Spanish in a rather dopey and insulting manner.
The film is a self-promotion film, the type MGM often filmed in color during this time. The purpose was to highlight a variety of their stars and thinly veil it in a visit to Santa Barbera for a yearly festival. During the course of the film, you see cameos by Warner Baxter, Harpo Marx, Ted Healy, Judy Garland, Gary Cooper*, Gilbert Roland, Leo Carillo, Robert Taylor, Andy Divine and many more. Several were likely chosen because of their Mexican-American heritage (Carillo and Roland) and no doubt Baxter was chosen since he'd already played The Cisco Kid in several films. The most interesting cameo to me was Ida Lupino, as this was before she became a star and underwent a HUGE makeover. In fact, you can't even recognize it's her until they say her name.
The overall film is extremely colorful (since these shorts were among the few pictures MGM made in full color), festive and plot less. For the average viewer, they'd be a bore but for old time movie fans they are a great opportunity to see many of your favorites.
*I have no idea why Gary Cooper keeps appearing in these films, as he worked mostly for Paramount and Columbia Studios. Maybe he just liked hanging out with the MGM starlets.