No, that's not an optical illusion -- it's just the extra walking space you'll get when you have a French door refrigerator gracing your kitchen. The double-door design uses one of the best features of a side-by-side model: narrow doors that don't swing as far into the kitchen as a full-width door, leaving more space in front to move about. That'll come in handy when your kitchen's crowded during a house-warming (or even a "come check out my new fridge" party). It's also great for small kitchens or kitchens with an island, because getting a snack won't block the traffic flow.
The best part is that even though the doors take up less room, you're not sacrificing any refrigeration space; it's still a full-sized fridge. And an added bonus of the double doors is that they're not as heavy as the single door (especially after you've loaded it up with milk cartons and bottles of soda).