Hide and seek with a lens

We have 2 young boys the same age at home- Naksh (my nephew) and Raka (our dog). I am currently reliving my childhood watching them grow. Here is an image of Naksh hiding behind the curtain during a game of hide and seek.

Sizes:
Small: A4: 11.69 X 8.27 inches
Medium: A3: 16.53 X 11.69 inches
Large: 2 X 3 feet : 24 X 36 inches