Dramatic art in her opinion is knowing how to fill a sweater.

The line is a barbed, characteristically caustic put-down: it contrasts “dramatic art” (serious acting craft) with a reductive idea of female screen success—being physically attractive enough to “fill a sweater.” Read this way, it criticizes an industry (or a particular woman’s attitude) that equates talent with sex appeal and marketable curves, implying that such a view trivializes acting and sidelines performers who do not fit a narrow glamour ideal. The phrasing “in her opinion” suggests Davis is reporting or mocking someone else’s standard rather than endorsing it, using irony to expose how aestheticized femininity can be mistaken for artistry.