I use Image Capture to import photos from my iPhone. I noticed recently that it shows two copies of every photo in the Image Capture window, both in list view and grid view.
There is only one copy of each photo in the iPhone camera roll, and when I drag them to a folder it only creates one copy of each. So it's not really causing a problem, but I'm curious why it is happening. I first noticed it in 10.10.1, and it continues in 10.10.2
See the screenshot below for an example. It is displaying two copies of IMG_6173.JPG and two copies of IMG_6172.JPG. There's only one copy of each in the camera roll. If I select all four and drag them to the desktop, it will create only one copy of each.