David Bordwell wrote a post about film criticism, “In critical condition”, which is worth a read.
He lays out four activities of the critic–describe, analyze, interpret, and evaluate–and relates these to three types of format: review, academic article or book of criticism, and critical essay. The evaluative activity becomes a key part. Such as analyzing films without evaluation:
I have written about a lot of ordinary films in my life. They became interesting because of the questions I brought to them, not because they had a lot going for them intrinsically.
And the role of taste and judgement:
There’s no accounting for [taste], we’re told, and a person’s tastes can be wholly unsystematic and logically inconsistent… The difference between taste and judgment emerges in this way: You can recognize that some films are good even if you don’t like them.
And on the critical essay:
The critical essay is, I think, the real showcase for a critic’s abilities. We say that good critics have to be good writers, usually meaning that their style must be engaging, but it doesn’t have to explode at the end of every paragraph. More generally, in a long essay, you are forced to use language differently than in a snippet. You need to build and delay expectations, find new ways to repeat and modify your case, and seek out synonyms…Just as important, the long piece separates the sheep from the goats because it shows a critic’s ability to sustain a case. The short form lets you pirouette, but the extended essay—unless it’s simply a rant—obliges you to show all your stuff. In the long form, your ideas need to have heft.