No matter what she says, she's beautiful. When they are moving her from Melanie's body, into Pet's, he doesn't feel any of the revulsion, any of the hatred that she said he would.
All he feels is awe, holding her in his hands and touching the most exposed part of her. It flutters in his hands, like a butterfly. He barely remembers them, flying free in the open air as he hasn't been able to do for so long, but he remembers one landing on a bush right next to him, a few years before the invasion, and watching it until it flew away with the sunset.
This here, in his hands, is Wanda, the woman he fell in love with, not whichever body she happens to be in.
Because he knows now that Wanda is no longer there, Melanie will have no appeal for him.
He will not care - not like he used to.
He's got Wanda, in this new body. Ian had refused to go with them when they picked the body out, refused to leave her alone. Because he doesn't mind what body she ends up in, as long as she's happy.
Because he never really cared about the shell.