Open-ended toys generally stimulate more creative thinking and foster different mental connections than toys that simply direct children to do a specific thing or build a defined object.
By "open-ended," I mean toys that are child-driven instead of instruction-driven. If a child is told "these blocks form that truck on the cover of the box," that may be where the child begins. Without the specific instruction, the child builds first and defines later: "Look, Mommy, I built a dog." In short, the child has thought and imagined on his or her own. Voila, new connections!
While it's certainly satisfying and valuable to solve the puzzle of building what you see in the picture, I think the nature of childhood development is better served by toys that teach them the joy of imagining, dreaming and then creating to THEIR specifications, whatever they may be.
Agree? Disagree? Let me know what you think.
Ken