I think you may have a misunderstanding of what the mother rabbit caring and nursing process is. If she had the kit yesterday morning, it's barely been 24 hours at this point. And it can be 24-36 hours before a mother rabbit will feed the kits for the first time. Until then it's perfectly normal for her to completely ignore them. But no more than 36 hours before she nurses the first time, or it becomes necessary to intervene or kits can become too weak to nurse.
That kit isn't looking too dehydrated and wrinkly to me. So it may have got some milk from nursing. Usually how you tell is they'll have a big fat belly. You may even be able to see a white splotch where the belly is full of milk. Kits that haven't nursed or aren't getting enough milk, won't have a fat belly and may start to look wrinkly and dehydrated. They will start getting weak as well.
Kits usually only nurse once, maybe twice a day, in the early morning or late evening. The rest of the time the mom pretty much ignores her kits. It's her milk coming in and creating pressure in her nipples, that should prompt her to hop in the nest to nurse. A reason she may not take care of the kits is her milk didn't come in, or she's a first time mom and confused about what to do.
If the kit doesn't have a full belly after trying to nurse, the mom may not be producing milk or enough milk. Let the kit try from several nipples. But if still no luck, hand feeding formula may be necessary. It's a last resort though, as aspiration is a big risk from hand feeding kits, which would prove fatal if it happens. So nursing from the mom is best, when possible, even if you have to assist.
If the mom is a danger to the kit by stepping on it or trying to scratch or bite it, then yes, I'd keep the nest box removed (indoors), and only return the kit in the morning and evening to see if mom will nurse on her own, supervised by you to make sure she doesn't harm the kit. Or assist the nursing if needed to keep the kit safe if mom isn't cooperating or is trying to hurt the kit.
Sometimes her deciding to hop in the box to nurse, is catching her at the right moment when her milk is full and prompting her to want that release. So that's something to watch for and try and coordinate the timing of when is the right moment to bring the kit for nursing.
You'll need to start increasing mom's feed. She needs free fed good quality grass hay always, topped with new hay daily. And her pellet amounts will need to be increased a lot as she is nursing more and the kit is growing. If her pellets are a grass based pellet and not alfalfa, I'd suggest supplementing her hay with some good quality alfalfa hay, as she'll need the extra calcium and protein that is in alfalfa hay, for milk production and nursing.
And make sure the baby is staying warm, since it's a single. There should be a pile of fur for it to burrow under to stay warm. If mom didn't pull enough, see if the fur on her belly or dewlap is still loose enough to pluck. Plus it helps to have some of that belly fur removed for the kit to nurse. I'd line the nest with soft grass hay. It can go over the shavings if you want. Then create a shallow bowl shaped hollow the kit can nestle in under the fur to stay warm.
The reason to add soft hay, is it's good for when the kit starts nibbling on solid food at around 1-2 weeks old. Good quality (no mold, no moisture, no weeds, low dust) grass hay is the absolute best solid food for kits to first start eating as it's low in carbs/sugars and high in fiber, which is the best for rabbits digestion and least likely to cause enteritis issues in baby rabbits.
These links have some good info for baby rabbit care, also a picture of what a kits fully belly will look like.
https://wabbitwiki.com/wiki/Pregnant_rabbits
https://wabbitwiki.com/wiki/Baby_rabbits_(domestic)
Rabbits have 2 uterine horns, so it's still possible for her to have another set of kits several hours or days later. So if you've removed the nest box with the kit, you'll need to provide another nest box and lots of hay for her, in case she does have more kits. I'd leave it in there an extra 3-5 days.
