(IMAGE: NETFLIX)

It can be hard deciding how to evaluate a certain type of Netflix Original Movie. Take the new Jack Black passion project “The Polka King,” for example. It’s based on a true story (and a documentary) about a charismatic Polka band leader named Jan Lewan. Lewan is a Polish emigre from Hazelton, Pennsylvania whose passion for music was exceeded only by his greed in bilking seniors out of their lifesavings–a Ponzi scheme the movie presents as almost accidental.

Directed by Maya Forbes (“Infinitely Polar Bear”) and co-scripted by Forbes and Wallace Wolodarsky, this is a frequently brainy and at times scabrous satirical farce–a kind of “I, Tonya” light about a delusional go-getter who wrote songs with titles like “Polka Bubbles” (Don Ho Estate, call your attorney!) and “Proud to Be an American,” and whose screen incarnation earnestly declaims that he has “America up my wazoo!” The film hits a kind of sweet spot for Black too, who plays to his strengths as a hipster ironist (a character who takes Polka seriously is almost the definition of hipster irony) while displaying the indie acting chops he’s been cultivating since at least as far back as “Margot at the Wedding.”

And yet as a movie “The Polka King” has some issues. One of them, remarkably enough, is Jacki Weaver, the great actress probably most renowned in America for originating the homicidal Ma Barker figure in David Michôd’s original Aussie version of “Animal Kingdom.” Weaver is a talent of absolutely limitless resources, all of which have been deployed simultaneously in her portrayal of Lewan’s harridan mother-in-law in a performance of almost operatic miscalculation. Hidden behind a curly fright wig, leopard skin polyester blouses and a pair of Gloria Steinem eyeglasses with frames the size of passenger jet windows, Weaver looks and acts like a refugee from a high school production of “Hair Spray.” Every vocal inflection has the calculation and volume of an old school Hanna Barbera cartoon voiceover–in a perverse way, she’s singing her role at least as much as Black does in the many many Polka performances featured.

Weaver is too shrewd an actress to be caught out this way for no reason, and Maya Forbes is too skilled a director to shoot so much of her movie in claustrophobic close-ups without recognizing how they amplify the generalized mugging. But that’s only if this is a movie–meaning a work designed to be seen in a theatre–not if it was created to be watched on a phone.

Have you ever watched a comedy on a phone? It has so much to compete with–the world, your lunch, the almost certain possibility you’ll receive a call or a text message some time during the next hour and a half. Forbes directed “Infinitely Polar Bear” pretty much in medium shot if memory serves. But that was four long years ago, before the tectonic plates of visual media formats clashed so hard against each other that the gigantic Rupert Murdoch Fox empire decided to sell itself off in pieces because it was too small to compete with streaming.

If your movie is itself a kind of handheld device, maybe it’s smart to shoot the faces. Maybe Jacki Weaver knows of some sweet spot somewhere between a thing in your fingers and a human nose where that kind of bigness gets reduced to comedic genius.

And if that’s so, how do you evaluate “The Polka King’s” subtleties? Because it has some that might be lost if you subscribe to Trump’s Twitter feed: A wry feeling for 25 year old small market TV production values. A sly awareness of how big grudges lurk in smalltown life. 

Jason Schwartzman is unerringly wonderful as Lewan’s hangdog arranger and clarinettist Marty “Pizazz”–he amps himself up to match the bigness of tone while remaining psychologically true. SNL veteran Jenny Slate channels Judy Holiday by showing how an unsophisticated woman isn’t necessarily dumb and that there is occasional strength in the weakest of us.

What carries the day ultimately is Jack Black’s unwavering likability, which gets a full workout in a movie where he’s almost never offscreen. Like the late John Candy (whose deathless SCTV Polka god Yosh Schemnge Black sometimes recalls), Black is our national pudgy uncle, the guy who does funny voices for us, and covertly passes us a five dollar bill when he’s leaving the party and takes our 11 year old hand.

The funny voice here–Black’s “Polish” accent–is another matter, four parts sketch comedy to one part Meryl Streep.

I wonder how it’ll play on a phone.