With the notion of attentively considering (κατά, down into, or through; compare εἰς, into, Jam 1:25). Compare Luk 12:24, Luk 12:27; Heb 3:1. So that the contrast is not between a hasty look and a careful contemplation (Jam 1:25, looketh). It is not mere careless hearing of the word which James rebukes, but the neglect to carry into practice what is heard. One may be an attentive and critical hearer of the word, yet not a doer.
His natural face (τὸ πρόσωπον τῆς γενέσεως)
Lit., the countenance of his birth; the face he was born with.
In a glass (ἐν ἐσόπτρῳ)
Better, Rev., a mirror; a metallic mirror. The word occurs only here and 1Co 13:12.