Four years old, wrapped in pink rubber rainwear, golden curls spilling from beneath her hat, feet dangling above the floor. She stares at the screen with the same absorbed intensity as everyone else packed into this underground carriage on a rainy Thursday. All of us in our private zones, creating our reality through the 6.9-inch glass mirror.

Then I realise the only difference: her phone is just a plastic square.

Like everyone else, she doesn’t move, utterly transfixed by the tiny sticker screen featuring a unicorn. Without shifting her gaze, she slowly sticks out her tongue and licks the fake screen with deliberate strokes. A moment later, she locks her eyes on me while dragging the screen across her cheeks, rubbing her forehead, eyelids, and chin.

Weirdly sensual, oddly precise, a perfect mime of devotion to how we all feel about our squared portals.