Is there any canon proof (written or televised) that shows Weeping Angels to be immune from seeing themselves? It stands to reason since they cover their eyes (seeing their hands would quantum lock them), but I don't remember it actually saying.
Edit: Each individual angel being immune to itself, like looking in a mirror. Not looking at each other. Like an angel that looks at its own hands, would it not quantum lock itself?
Angels are not immune to the view of another angel. The Doctor used this fact to trap them in the episode "Blink". He enticed them to surround the Tardis, then when it was removed they were left looking at each other. .
The Doctor, Amy and Rory neutralised the Angel by making it make a duplicate
of itself through its reflection on a mirror. After a brief panic of more Angels
appearing, the mirror was smashed, leaving the two Angels in quantum lock.
As far as I can tell, there are two issues at work here:
Can an angel lock itself by looking at part of itself, say an arm or a hand?
Clearly not, as pointed out, they cover their eyes, which would de facto risk locking themselves. Given that they lock instantly, chances are they cover their eyes a fair chunk of the time. The nature of the Angles is to be observed, if you get existential, the Angel already "knows" of them-self can thus can not observe it in the same way as an outside creature.
Can an angle lock by looking in the mirror.
In this case yes, the image of an Angel becomes an Angel, and thus observe each other. Possibly locking each other.
One could argue that the image is an EXTENSION of the original angel, but evidence points to counting as a separate entity (although the angels do have some signs of telepathic or hive-mind properties)
Ok here's the final answer for this question: Yes, an Angel is immune to seeing itself. That's without a mirror. Because in all the episodes, the Angels had been able to more even after hiding their faces.
In "The Time of the Doctor", a Weeping angel is revealed to actually not be completely immune to seeing its own form, as shown by the mirror the Doctor places with the message attached; "WITH LOVE FROM THE DOCTOR!".
I'm by far not a Dr. Who follower since I've only watched some episodes, but if an image of an angel is an angel (episode 64) then it stands to reason that a mirror image of an angel is another angel and it would make perfect sense that these two angels would be locked (like in a previous episode), until one is moved out of the visual path. If this is not doable, then there's a storyline hole.