i'm not super experienced at baby critiques, so i'm not always able to distinguish between "ugly duckling may grow out" and actual conformation flaw, so i may be off on some points.

Chestnut:
starting from the top: not a super "TB" head, but cute enough; a bit thick through the throatlatch; good length in the neck, decent length through the neck, but it's very straight - could be better once in training to develop that topline, but it's not going to be spectacular; ties in well enough with the shoulder; rather upright, closed shoulder - not good for hunter movement, and not good for being adjustable over any course; looks over at the knee; rather upright pasterns, and even though you can't see them properly, it looks as though her front feet are very small - neither of those things are conducive to being a successful, sound horse over fences; good depth through the girth; nice length through the back; she's standing camped out, so the hind-end is harder to critique, but i do not see a powerful hip; she looks to be quite cow-hocked, also carries her hocks quite high - again, not conducive for good hunter movement, or ability o/f; hard to tell from this angle, but one pastern looks upright and the other does not, her near leg looks to be turned towards us, fore-shortening the angle, so who knows. her fetlock joints look swollen on both legs, like she's stocking up. again, because of the wonky stance it's hard to say, but those hind legs look quite straight for a hunter or jumper prospect.

Bay:
more classic TB head; maybe a bit thick through the throatlatch again, but hard to see since she's stretched out; very similar neck to our first filly - quite straight; ties in a bit low to the shoulder; rather upright shoulder, but less closed than our top filly; loong upright pasterns; again, good depth through the girth, nice compact body; good length over the back; better hind end than our first girl; hard to see properly since one leg is way under her and the other is way back, but she appears to have better angulation through the hock; hard to see her hip because of her leg position, but all in all, her quarters look more powerful. again, i don't think i like the pasterns on the hind legs, but it's hard to properly see.

If i had to choose one as a hunter, i would go with the bay; however, the front pasterns on both worry me in terms of looking at either horse for a career o/f. I think your friend thinks the chestnut looks more like a jumper than a hunter is because, comparatively, the bay is more "type-y" and the chestnut has her neck set on a bit higher, which is more common and sought after in jumpers.