Drinking glass drawing seems beyond the limits of what humans should be able to do.
Not previews of work-in-progress manga panels or anything, just some non-narrative artwork he’s been doing to sharpen his already razor-keen capabilities.
And when we say Murata “made” it, we don’t mean he crafted an actual drinking glass, because as realistic as it looks, that’s still a drawing!
What we don’t know, however, is whether or not Murata is human.