Basic emotion method and "accuracy"

Chapter 3 endnote 5, from How Emotions are Made: The Secret Life of the Brain by Lisa Feldman Barrett.
Some context is:

Test subjects from all around the world (Germany, France, Italy, United Kingdom, Scotland, Switzerland, Sweden, Greece, Estonia, Argentina, Brazil, and Chile) choose the expected word or face about 85 percent of the time on average. [...] In the basic emotion method, choosing the expected emotion word is called “accuracy,” which is a misnomer.

The basic emotion method seems simple—just match a face with a word or story “accurately.” But if you think about it, “accuracy” is a misnomer because the photos are posed, not taken during spontaneous instances of emotion, so there is nothing to be “accurate” about. Moreover, we’ve learned that there are no objective fingerprints of emotion, so there’s no way to check “accuracy.”

Instead, the theory of constructed emotion reframes the question in terms of expectation rather than accuracy. Did the subject choose the emotion word that the experimenter expects? This is what scientists call “agreement” with the experimenter’s expectation.