[Kozak]

It's an internal reflection from the camera's optical system.

[Old Professer]

I agree, the larger is the mother and the smaller is the daughter. IMO

[Sans-Culotte]

The photographer seems to have seen the objects before taking the photo (unless she only saw it through the viewfinder or lens).

[Old Professer]

Let me make myself clear; the mother would be the bright white lights at the lower left and center of the image and the blue lights the daughter images.