Looked a lot last night. From what I can tell, no video footage will have a capture that is useful.
So it must be a photo. The photographer is really well known in DC and has taken lots of major political photos. He wasn't just some random person with a cell phone.
That being said, if Q asked us to find it, to me that implies that it is out there somewhere and possible to be found.
Now, the photographer who took the photo for Getty has already photoshopped his images. He obviously wanted a scoop and wanted to release the image (it's gone viral) but without the words on the screen. So he cleaned it up before Getty released it.
So, short of him/Getty voluntarily releasing the raw file, how can we find the raw image? Well I suppose someone who knows how could find his files and obtain the originals. Short of that, perhaps someone else with a cell phone also took a photo of this cell phone screen and it is online waiting to be found. I searched through FB, Instagram, Twitter last night but didn't find it.