When your body blocks light from hitting certain portions of the screen, those areas don't absorb light. As a result, when the lights go off, the blocked areas remain dark because they didn't absorb light to begin with. On the other hand, the exposed areas emit the stored light, creating a bright glow. This contrast between the glowing and non-glowing areas forms a shadow where your body blocked the light. It's a fascinating interplay of absorption, delayed emission, and darkness that creates the intriguing effect of a glowing screen with shadows.