Where The Wild Things Are - S4-E18
Visible crew/equipment: In the scene where Xander and Anya make the last attempt to rescue Buffy and Riley, Anya is attacked by some vines and you can see another set of hands from the crew pushing the vine towards her.
Where The Wild Things Are - S4-E18
Visible crew/equipment: Toward the end of the episode Giles, Tara and Willow contact the spirits. Just after the spirits vanish, in the bottom left corner of the screen a crew member's leg is visible.
Visible crew/equipment: While Xander tells the gang about the "demon" he encountered, they all walk into Giles' apartment, and just as Xander heads up the stairs, the white T-mark taped to the rug is visible under the corner of the desk with the lamp, where Willow will stand. (00:27:00)
Visible crew/equipment: When Willow does her spell to save Tara, you can see the black pad Tara falls/ stands on.
Visible crew/equipment: In the final scene with Anya and D'Hoffryn the edge of the backdrop (and the set behind it) is visible when D'Hoffryn walks around her. (00:40:10)
Visible crew/equipment: While Buffy, Giles, and the gang are in the library fighting the demon that came out of the Hellmouth, the camera zooms toward the door that leads into the hall, where you can see Xander being chased by the dead guys. As the camera zooms in closer towards the round window in the door, you can see its reflection in the glass when the strobe light flashes. (00:36:10)
Chosen answer: From what we see in the series, certain girls are identifiable as potential Slayers - Kendra clearly fell into this category. The identification method is presumably mystical in nature, but the Watchers' Council are pretty effective at that sort of thing, so they're quite good at tracking down the potentials ahead of time. Not perfect, though - it does appear that Buffy herself may have slipped through the net - certainly she had no inkling of what she was until she'd already taken on the role of Slayer. It is possible, however, that this was actually cultural - an American family would hardly be likely to turn over their daughter to some strange man for 'training', so the Watchers might have chosen to keep an eye on her covertly, whereas some other cultures (like Kendra's Jamaican parents) might be more willing to believe.
Tailkinker ★