SHE'S PERFECT BARBIE. HE'S SCENE-STEALING KEN. THEIR LIFE IN PLASTIC LOOKS FANTASTIC

For someone who’s 11.5 inches tall and weighs under 8 ounces, poor Barbie’s had to carry an awfully heavy load over the years on that slender, plastic back of hers

Welcomed as a trailblazer in 1959 — An adult doll! With actual breasts! — she was nonetheless branded an anti-feminist a decade later when women’s rights marchers chanted “I Am Not a Barbie Doll,” referring to her unrealistic body type (and perhaps ignoring the fact that she was single, a homeowner and a career woman).

As years went by, Barbie had her hits (adopting a more inclusive body type, running for president) and misses (exclaiming “Math class is TOUGH!” — ouch). Through it all, this lightning rod in tiny pink heels remained uniquely talented at reinventing herself.

Which is why it makes sense that now, writer-director Greta Gerwig takes Barbie in more than one direction – in every direction, really – in her brash, clever, idea-packed (if ultimately TOO packed) and most of all, eye-poppingly lovely “Barbie,” the brand’s first live action movie.

Is it a celebratory homage to Barbie and her history? Yes. Also a cutting critique, and biting satire? Yes, too. The film is co-produced by Mattel, and they must have felt skittish about some elements — perhaps not Will Ferrell’s reliably buffoonish Mattel CEO, but a far more serious scene where a young girl accuses Barbie of making girls feel bad about themselves. The movie’s also about gender dynamics, mothers and daughters, insidious sexism ... and more.

But the neatest trick is how “Barbie,” starring a pitch-perfect Margot Robbie — and after a minute you’ll never be able to imagine anyone else doing it — can simultaneously and smoothly both mock and admire its source material. Gerwig deftly threads that needle, even if the film sags in its second half under the weight of its many ideas and some less-than-developed character arcs.