They are prey animals so they won't give birth of they don't feel comfortable with the spot or if they think anyone is watching.
When it's time, it's time, and someone watching isn't going to make any difference. I can't even begin to count the number of litters that have been born while I was nearby. I still remember walking down the aisle of my rabbitry, looking at the rabbits to my left, when something made me stop and look to my right. The doe in that cage had a mouth full of hay and was standing on her hind legs, front legs on the cage door, silently screaming at me "GIVE ME A NEST BOX!!" (I had lost track of her breeding date; I should have put a box in days before). I grabbed a box, shoved some hay in it, and put it the corner she had chosen. She jumped in, rearranged the hay a little, and began pulling fur. When she jumped out, maybe 20 minutes later, she had a lovely, lively litter in the box, and an apology from me.
If I have a doe give birth outside of the nest box, if the babies are alive, I put an appropriate amount of hay in the box, and whatever nest material the doe gathered, then put the babies in the box. Most does go right on from there without any problems. During cool weather, I may even take the babies in the house and only bring them out to mom once or twice a day. If I have a doe due to kindle during a cool spell, I will put her and her nest box in a carrier, and put them in my hall closet (I call it my "maternity ward"). If I have a first-timer that doesn't nurse her litter, I will put her box in small carrier, put her in the box, and close the lid on the carrier; it usually only takes a time or two for the doe to catch on. Most of my does have done exactly what they should, even with all my interference. When I first got into rabbits (30-odd years ago), I heard all the "oh, you can't, you mustn't, yadda, yadda, yadda." Maybe all of that was true a hundred years ago, but talking with other rabbit breeders taught me that rabbits of today are a lot more tolerant than we have been led to believe, and they will often adapt to whatever we see fit to do (within reason, of course).