What does he alter?

EVERYTHING!

"Hi John, I'm making eggs, bacon, toast, and Orange Juice", "I'd rather have a glass of breastmilk...freshly squeezed" he says joking around giving Julie a hard time. "Sorry mom...sounds good thanks I'm starving"!

With a snap of his fingers John bimbofy's his mother so she won't question the changes he'll make next. First Julie's hair transforms into beautiful light brown shoulder length feathered curls, her eyes are restored to their lovely blue hue; Next her wrinkled sagging skin firms up regaining its smoothness and elasticity as Julie's age spots disappear...vagina, hands, arms, legs, & especially her breasts as John gives his mom a lovely full 33B ample bosom.

He tightens her pussy making Julie a virgin again so he can 'pop his mothers cherry', then he makes her fat disappear returning his mom to her thin & svelte 165 pound slender attractive self. He shrinks her fat overweight ass to a small petite Jenna Ortega look like his sisters. Finally he makes his mom taller, adding some height to her 5'4" form as Julie's legs lengthen 5 inches.

Lastly John makes it so she'll only look this way in his presence, if anybody else is around they'll see her as she looks normally.