There's something about a bedroom that makes us want to incorporate perfect balance and symmetry. It may stem from the fact that the bed is already divided evenly and we like the ease of building upon that vibe...
In the bedroom, it makes perfect sense that each side of the bed has a bedside table and lamp. Adding the decor becomes easy and effortless because you're building upon the rule of symmetry. And while your objects don't have to be identical we do like the simplicity of duplicates in the bedroom. We find that when there's balance in the bedroom, our lives run a smoother course (and it doesn't hurt to enhance your feng shui).
(Images: 1. kimdimsunshine 2. Bedroom Month: Best Bedroom Makeover, 3. The Power of Color: House Beautiful, 4. Inspiration: Good Ideas From Constanca's Home, 5. Look!: Picture Frames Around A Bed)