好问题，谢提问！答案有点儿绕脑但很有趣。见这里：。。。

Earth and moon each orbits at its own axis, and there is a angle between them:

as a result, the moon will return to the same position in the sky about 50 min and 29 s later each night. Therefore in the picture, since the moon was photoed from the same location on earth and at the same time each night over a month, it would not appear at the same position in the sky where it appeared 30 days ago.

To take a picture of the moon that will show it appearring at the same position 30 days ago - following the pattern of 8 and known as a "analemma", one has to take a picture of it each night 50min29s later than last night. Then the moon's path in the sky over a month will be an analemma: