Are We Seeing the Sun in the Distance?

This is a video of a weather balloon shot at night time. In the distance we see what the creator of this video says is the moon. I don’t know where and when this was filmed however it may not be the moon. Not knowing about perspective and “atmospheric blocking” of light could lead someone to automatically conclude it is the moon because from the point of the balloon, it’s night. How is the moon perfectly full? Why is it so bright? Some might say the camera was set on low light setting. If the sun is far away on the flat earth, from the balloon cameras point of view it will not be able to see the lighted up ground below the sun but rather only the very top of the highest clouds below the sun and that is what we see at 6:45. In the distance it could be a bright sunny day and from the balloons point of view it could only see black. It may be the moon?