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Parents buy toys by imagining their child's face when it's opened. A toy on white tells them what's in the box; the same toy in the middle of play tells them it will be loved. The best listings show both, with the age range obvious at a glance.
Toy shoots are notoriously hard to run. Children have short attention spans and strict working hours, sets need to look like real playrooms, and every piece of a multi-part set has to be visible and accounted for.