Say huh?
The dev has a built-in patch system, where you just change patch false to true, and it unlocks said content, but it's not implemented fully.
But the updated patch with images definitely works, just tested it again with a new install/game, shows "Mom" on the phone call, he says "Hello, Mom" and so on.
There are other parts of the game the way he codes it that sometimes his own code doesn't do what it's supposed to do as it was probably lifted from some other game (not my words, words from another mod/patch maker).
Read above, the dev implemented it to where it's just a switch, but it doesn't always fire like some games where the game has "2 scripts" if it's false it fires the non-incest one and with "true" if fires the incest one.