A step saves the current space, where you stand (the class gathers there) and what's playing on a media screen. Title it, write the narration, optionally open a station card.
The bar moves when you speak. The line is your sensitivity gate.
Pick an item, then click to place it — on the floor or on top of another item (laptop on a desk, plant on a bookcase). Keep clicking to place more; right-click or Esc to stop. Click a placed item to select it, or drag across empty space to select several (Shift-click adds one more). Drag to move, scroll to rotate (or R / Shift-R), Del to remove, paint swatches recolor — all of it applies to the whole selection. Right-drag looks around. Everything is saved with the world.