Can you help me to identify this type of art style?
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It has realistic proportions, and emphasizes shading and tonality through hatching and delineating clusters of shadow.
It focuses on details, on characteristics of the sitter, so it's very likely (intended as) a portrait (and not a type), yet the overall impression is one of swiftness, of rapid gestures, and intentionally made to look like a sketch (intentionally, because this was posted as-it-is, in a clean state, and because the image is well-balanced and in the same stage throughout—indeed, all the drawings on the artist's Instagram are in this style).
As far as this is not a personal style of the artist, I'd say this is illustration done in the style of concept design/design concept: it's a rapid but clear construction of a specific subject.
The following are the first results currently shown on the Google Images page when searching for 'concept design drawing':
As always, this is only an attempt to frame it within existing, broader styles—this could very well be the artist's personal and idiosyncratic style (but in that case, they seem to be influenced by conceptual design illustrations).