I don't think it's a reflection. It could have been something near the camera's lens as it appears out of focus. Cigarette smoke, steam, mist, or breath (if it's cold) can look like ecto in flash pictures--I can speak from experience with this as I captured my own breath when taking pictures of my house after the fire.
I always ask if there's paranormal activity observed in the location where the picture was taken. This increases the chances that it's "real". But it's often difficult to distinguish real orbs from dust or ecto from smoke/mist in pictures.