Question about the MIY and his shapeshifting (SPOILER)

So we know that the MIY shapeshifts into Sophia for this cycle. My question is, why? The obvious answer is to hide his identity but here's my train of thought.

When Victor was talking to his father about the MIY in this episode (s4e4) he said that he appeared in a car like the rest of them, they welcomed him in, but then he ended up being a monster. Victor remembers him as we see him in his "original" form, the yellow suit. But if - and I'm assuming - that the MIY changes form each cycle to hide his identity, why would he need to if there's nobody left from the previous cycle to recognize him? The goal in each cycle is to wipe everyone out and then start over with new people, right? So does the MIY know about Victor and him surviving, which is why he shapeshifts? If so, this would seem odd because we have not yet seen Sophia/MIY see or interact with Victor in order to know if she recognizes him, therefore we would be left to assume again that the reason for the shapeshifting is to hide his identity from...nobody?

I suppose the easy answer could be because he looks scary as he is now (raggedy teeth, bloodshot eyes, etc) but since he shapeshifts he could easily change his appearance to look clean again.