He doesn't look severely underweight to me. His face is thin, but men have less facial fat and tend to have sharper features. He is vascular, but he is a man, and men are much more vascular than women. There doesn't appear to be muscle wasting or a lack of vital fat on the face. In many videos he is carefully angling his face to appear as thin as possible - shooting from the top down to emphasize his cheekbones, or occasionally visibly sucking in his cheeks, like here. This is a relatively common trick.

In the photo you posted of his body he is very clearly sucking in and has a pooch. I went though his other videos looking for decent shots of his body, which are rarer than I thought they'd be given his apparent confidence in being a skinny kween.

He lacks the protruding ribs that a severely underweight person has even when laying flat.

This is probably the video in which he appears the thinnest, and he is both covering his clavicle and very obviously sucking in. Tell me why his ribcage is so visible here as opposed to when he is laying down, when the stomach will be naturally at its hollowest-looking. His somber facial expression could partially be him holding his breath.

In an underweight person, the clavicle should be highly visible even with the shoulders at rest.

His hand isn't at all the clawlike hand of a severe anorexic.
These are severely underweight anorexics, for reference, which he does not resemble at all except in his God-given male shapelessness:
And here are some pictures of severely underweight anorexic men:

He might be TRYING to ape Eugenia, but he's nowhere near where she and many, many other anorexics are. He's using every old Livejournal/MyProAna/Tumblr trick in the book to appear that he is, but he's not.