Unfortunately you can’t sex babies until they are at least three weeks old. Once they are, you can press down just above their anus and their genitals should “pop” out. If there is a hole at the end of the protrusion, it is a male. If there is a slit/line at the end of the protrusion, it is a female. Hope that helps!
You can sex newborns, well, some people can, or is it that some rabbits are more easy to sex?
Anyway, I'm not one of those gifted people and can't tell anything conclusive from this pictures, but maybe this can help:
You can sex them as early as your skills allow. Just keep in mind that when they're only a couple of days old you really need to be gentle. Personally, I wouldn't try on kits as small as those. I'd wait till about 2 weeks then press gently on both sides of the protruding bits. The pressure will make the inner parts pop out enough to tell if the opening is round or a slit. Be forewarned that many experienced breeders have had their kits visited by the sex change fairy so check again in another week or two.