During the opening scene in the Magic Box, in the shot at 1:07 you can see a crew member's head moving at the left edge of the frame beyond the top of Tara's head.
Throughout the opening scene in the Magic Box you can see the boom microphone reflected 11 times in the glass of the display case behind Buffy. The first is at 0:06; the most obvious is at 2:17 (when the boom sweeps across, tracking Buffy); and the boom operator is visible as well in the reflection at 2:35.