conceived of as vs. conceived as
I disagree with JLG's explanation. Your supervisor is conflating two similar-looking but non-identical constructions having two different meanings:
1) To conceive of X as Y, where conceive means to interpret / comprehend:
Copernicus conceived of the Earth as a sphere rather than as a plane
2) To conceive X as Y, where conceive means to invent, especially when the invention is in pursuit of a particular objective:
Julius Edgar Lilienfeld conceived the field-effect transistor as a solid-state replacement for the triode.