>>719allegedly it is daytime, as there is light. and as far as i know if there isnt an atmosphere the sky cant be lighted up. for the lack of stars it is like anon mentioned allegedly because its adjusted to the sunlight and makes sense.
however when you watch the livestream (linked in the OP) and skip back to where it becomes dark (usually it goes so dark you dont see anything anymore) you wont see stars, nor citylight. and i assume a camera you shoot into space would be good enough to adjust to the brightness if my iphone camera is able to do that.
i heared about a theory that only our atmosphere makes the stars visible and without it we wouldnt be able to see it for some reason, but didnt really look into that yet.