Our Earth on Instagram: "A simple test can reveal whether you are facing a real mirror or a two-way mirror. By placing your fingertip against the surface, check for a gap between your finger and its reflection — if there is a small space, it’s a normal mirror. If there is no gap and your fingertip touches the reflection directly, it could be a two-way mirror. Media: @ash.leyhedge #lifehack #interesting #viral"