Name one shared detail.
My own try
Read the whole different source
Story: A toy rabbit draws a bridge across a blue line and imagines visiting the other side. Procedure: Put the Bridge card across the blue line on this paper map. Then choose a toy picture to put beside it. The line is a drawing.
Adult reads the whole source neutrally when wanted; exact child-directed recording, pointing/sign/AAC/drawing/type/speech remain available. Match print separately; no voice/neatness/speed gate.