Obviously there are a lot of technical/structural reasons why Gone Home and Save the Date don't feature much (or any, in Save the Date's case) visual representations of their characters. Gone Home went very much down the Toy Story route, focusing on inorganic objects rather than squishy bodies because the affordances of their chosen medium are such that objects "look better." More on that in a little while. Save the Date is very much a DIY kind of piece with a DIY kind of aesthetic. It was made (I think?) on visual novel engine Ren'py; incorporating visual elements would have required a lot of work for comparatively little payoff within the context of the game. It really doesn't need that kind of representation of bodies, even though some pictures of Felicia would have been more conventional in the dating sim sense.
Gone Home, on the other hand, makes a pretty strong statement by largely disembodying Katie--and Sam, and Lonnie, and everyone else. In other first person games I think it's conventional to at least have arms (for holding weapons) that at least make gestures towards interacting with the environment even if the graphics aren't quite up to showing the action really well. Halo characters, I think, have feet. Often you can switch between first and third person to keep track of your character's body. Your body generally makes sounds--at the very least a weapon change sound effect, grunts of pain or exertion, etc. In Gone Home Katie's body is almost completely effaced. You interact with objects constantly by just making them float in the air, rotating them with no regard for how human hands work, and awkwardly throwing them down from a point matched to your aiming dot. The camera doesn't move to imitate walking, there's no footstep sounds (even similar walking simulator The Stanley Parable has footstep sounds). There's just a hint of the rustling of clothing when you crouch down, and the odd irregular stepping sound.
The near-total disembodiment of Katie makes the handful of creepy photos even more uncanny. I spend a good bit of my gameplay yearning for things like photos, and I hate them when I get them. The two pictures of Lonnie aren't quite as bad, but they're much more like slightly edited actual photos, which is almost as weird.
I've got no idea what's going on with the human body in this game. I know that it's a game about nostalgia, a nostalgia specifically for objects and technologies--though only in some cases the actual objects of the nineties. There's a lot of love for home-recorded VHS and cassette tapes, but whither the PlayStation, the Sega Genesis, the home computer? Two or three typewriters in a house in 1995?? But despite its obsessive and loving recording of obsolete objects, Gone Home is ambivalent about more human-oriented nostalgia. Other than the feminist punk moment that Sam and Lonnie immerse themselves in, nostalgia for actual life in the nineties is not the order of the day: DaDT, living in the closet pre-Internet, the alienation of the aging Boomers (the mother with her affair, the father trying to ride another nostalgia wave back into creative success, their crumbling marriage), etc. I see in this game a love for the stuff of 1995 (or, really, the stuff of 1983) without much love for the lives people are leading.
But that doesn't really explain why I feel like Gone Home HAS to seem so human-free, despite the supposed human you're supposed to be operating to play the game, and despite the very human love story you're discovering. Making it happen requires really an incredible set of contrivances, followed by an ambivalence in Katie that I still find difficult to swallow: she doesn't even call out for her parents or sister? Knock on the door before looking for the spare? Register concern in any way? You don't even out that the parents are on a couples retreat until more than halfway through the game--or at least I didn't. Why is this framing conceit, the emptiness of the home of any human bodies even when one is walking through it, so important?
I haven't figured it out. I think it's a sort of unsexy mix of partial answers: there is no way to render human bodies in a way to match the photoreal representation of the house and objects; the nostalgia of the piece is object-focused and humans are therefore aesthetically superfluous; if we could see Katie kneeling on the ground rummaging through her sister's Playboy magazines she would seem like the most awful voyeur; the feeling of the game requires an absolute loneliness, so that we might feel the magic of Sam's connection with Lonnie even more. These are practical considerations. I don't think I'll reach anything like a good thesis about the implicit ideology of this aesthetic/mechanical choice, although I'm sure such a thesis is possible. For now I'm satisfied to start a new subcategory in my mind of "Games That Absolutely Should Not Include Bodies."