How to hold: turn BOTH phones so the screens face
each other (screen away from you), 20–30 cm apart, parallel. The camera sits beside the screen and will
see the other phone automatically. You won't see your own screen — listen for the chimes: two beeps = incoming,
rising chime = done. Computer ↔ phone: prop the phone against the laptop
screen — phone screen facing the webcam, front camera toward the screen. Hold the camera
10–20 cm from the code: closer than feels natural is usually right.