This is just my personal opinion and speculation, but here goes.
Video cameras are different from still cameras. Video cameras capture moments the same way your eyes do, as a series of images that change over time, which is stored on a tape or disk much in the way that what we see is stored in our brain. Thus it makes sense that a video camera would see what we see, which is the illusion painted for us by whoever decides what grim reapers look like. If the truth were seen in one of these images, it would be replaced by another image so quickly that our brain would not register the difference. Still cameras capture a single instant, it is permanently the way it is and does not change, and therefore much more likely to capture the truth because it is not replaced with a different image a second later.
I think her real image in the polaroid was some kind of cosmic fluke, most likely triggered by what Betty was about to do. Because polaroids are still images, the image of Betty's real face, not her reaper face, was kept. This would jive with the plot and keep out an image of a reaper face we the viewers have never seen and would probably be confused by.   See 6 other replies

Thank you! I was beginning to think I was the only person that caught that, although I think it would make more sense to list her as "Millie" in the credits rather than "Un George." In the one episode with the video cameras, there's a listing in the credits for "Un Mason" as well.   See 8 other replies

I love Walter! he was such a good sport about his part in SG1   See 3 other replies

This show is hilarious!
I'm glad my friend turned me onto it!
Back to my marathon.
;)   See 4 other replies

It's just you.and your comment is lame.   See 4 other replies