Orb Representing Departed Dad?

Thanks to the reader who sent in this picture with the following note:

My father passed away in May 2008 and this was taken in his living room Dec. 28, 2008. His favorite spot was on this couch reading, watching television and napping for the past few years. One of the two women in the picture is his favorite daughter. There are 3 other pictures taken that day with orbs that look much more like the ones on the web sites. In this picture there is also an orb on the couch but very faint and 2 or three on the bottom of the black blouse the woman is wearing.(they are also very faint) I have not seen anything like this before and just wonder if it is unusual. No other pictures I have ever taken before or since
show the orbs that showed up that day.

I think what makes this orb distinctive is its brightness and luminosity. I have to wonder whether a mere speck of dust would “glow” like that.