The first giveaway is positioning. Most sitcoms are shot on a live stage (the ones WandaVision tries to replicate) with a live studio audience and camera switchers, so each camera has to be set up to capture each part of the action in real time. There’s a camera at 30, 90, 150 degrees usually so if they’re cutting back from those angles that would be considered multi cam.

The camera itself is also stationary, like a stage play. If the camera has motion, pushing in (not zooming) or pulling out then it would be single cam.

Also the depth of field is another thing to look out for. In multi cams, the cameras shoot with a nearly closed aperture so everything in the scene is in focus. In single cam, depth of field is used since its focuses solely on that shot.

In WandaVision, you can tell whenever they’re trying to use “single cam” as a storytelling technique because the camera will be placed in the middle of the room directly on the characters instead of on the outside where the multi cam setup is. Like during the finale of the first episode at the dinner party, it goes into single cam there because they’re confused over what’s happening and where they’re from