Esta questão foi discutida tanto na série de TV quanto nos romances em prosa que levam adiante;
Simplificando, um anjo chorão pode existir como uma entidade independente dentro de uma imagem de câmera ou vídeo. Se você visualizar essa imagem, o anjo fica congelado, mas assim que não estiver sendo observado, o Anjo pode se mover livremente dentro do quadro, bem como sair do monitor que você está usando para observá-lo.
Nós vemos isso mais claramente no episódio de TV "Time of Angels"
AMY: Doctor Song? Did you have more than one clip of the Angel?
RIVER: No, just the four seconds.
(The Angel is now looking straight at the viewer, hands completely lowered. The time stamp has moved as far as 00:11:28:04 before jumping back to 00:11:24:23. When Amy looks at the monitor again, it is closer to the camera. The module door closes and locks behind her.)
(Amy tries turning off the monitor, but it comes back on again, and again, and again. She moves close to the monitor.)
AMY: But you're just a recording. You can't move. (She tries to pull out the lead to the monitor. When she looks back up, the Angel is up close to the camera, but the time stamp is still running through the same four seconds.)
AMY: Doctor?
(Amy cannot open the door. The Angel's mouth is open.)
AMY: Doctor!