As best as I can tell, the artist made those Personas up, basing them on existing characters.
For example, the writing on Kyon's pic reads "Shujinkou (Main Character) &
Sakata Gintoki". Koizumi's Persona is
Barasuishou, and Yuki has
Zerogouki.
I can't quite figure out Asahina's Novuyo or Haruhi's Tenshou Taijin, though I seem to recall "Tenshou Daijin" as another name for Amaterasu. But I'm really bad with Japanese mythology, so I'm probably mistaken.