explainingproduction on Instagram: "The video depicts a privacy test where pressing a playing card against a bathroom mirror reveals a hidden laundry room behind it, adapting the classic "fingernail test" to expose two-way mirrors used for surveillance. Two-way mirrors function via partial light reflection: the reflective coating on the front surface allows visibility from the darker side when lighting differs, unlike normal mirrors with back-side coating, per optical principles confirmed in mat

2 guys have a different screentime ! - #screentime #success #productive #disicpline