A post at ErinSparler.com switches from characterizing baroque as “ornate” (as the dictionary does) to characterizing it as “realistic.” (Is ornateness regarded as inherently more realistic? Kitchen table tops might disagree.)
All I can gather from a quick investigation is that baroque is characterized mostly by “elaborate ornamentation,” whereas rococo is characterized mostly by “elaborate ornamentation.” American Heritage says that in music, rococo is “an extension of the baroque.” More ornate?
That the dividing line between baroque and rococo might be fuzzy is not what is confounding me; boundary-line fuzziness is endemic in many clearly defined concepts. That things in reality do not always fall neatly into one conceptual category or another doesn’t make the conceptualizations invalid or useless. But definitions do, if accurate, specify those instances of a concept which clearly fall within the boundary lines. (Many organisms are clearly plant or clearly animal, even if a few one-celled freaks are plantish-animalish.) If rococo simply means “baroque, only more so,” perhaps that’s what we should say.
I suspect that if examples of baroque and rococo art that the critic had never seen were mixed at random, he would probably not be able to say which is which. Not in the way he could tell whether a statue is from ancient Greece or from Renaissance Italy.