The insides of the distributor move. When you turn the rotor and reluctor side to side, you are moving the advance weights against the springs and the stops. This is normal.
The pickup and plate also move when the vacuum advance is sucked in, then released. You can watch it move by sucking on the hose with your cheeks, then holding the vacuum with your tongue.
As soon as it stops, plug a spare distributor on to the connector. Pull the center cap wire and lay it next to ground, then spin the distribitor shaft. If you get sparks, it is the pickup in your old distro.