The watching begins before the idol arrives
The modak tray goes to the left or the right, you're not sure which, and someone in the kitchen notices that you're not sure. Nobody says anything. That's the thing about your first Ganeshotsav as a bahu: the corrections rarely come as corrections. They come as a slight pause, a redirected hand, a mother-in-law who quietly moves the diya two inches without meeting your eyes. You learn the ritual, but you also learn that you were being watched while you didn't know it yet.