I don't know what it is, but it's awesome. Great picture.

Vicky

To me it looks like the flash hit something that was hanging from the ceiling  (being as there looks like there are a lot of cords that are hanging there). It is from there that there was light reflection that had caused the cause haze - as you can see it almost looks exactly like the white streak. The orb looking object could also be part of the light reflection.

This is just my opinion.