On the hypothesis that Paul is communicating that the “appearance” of Jesus here was purely intra-mental, it seems probable that the experience was a supernatural vision from God (the normal way God communicates something like this intra-mentally).
This is relevant because this language of “revealed his Son in me” etc. does not recommend a visual component at all, and so does not really accommodate the vision theory. So, by modus tollens, Paul is not communicating that the appearance of Jesus here was internal.
Paul decisively rejects the view that Jesus’ appearing to him was vision-like or purely internal to his mind.
• Paul: “Jesus physically appeared to me.”
• A feeling would not convert Paul.
• “Opthe” (pass.) implies a visual experience.