If you want more info on the packaging, it was discussed in depth at the latest round table discussion with Hasbro:
Q: Transformers boxes, can they go full closed box like other Hasbro lines?
A: Unlike Marvel and Star Wars, the Transformers brand skews younger, so seeing the robot inside does bring in more sales than a closed box with the image of the character. Transformers is not as character focused line like Marvel, it isn’t the character itself that sells the toys, it’s how the bot looks. There have been studies done and open windows are best for their target audience of 8 year olds seeing the robots on shelves. The leader class toys are higher priced and thus not likely an impulse purchase by parents, so they can look more like a toy aimed at collectors. Looking into all different boxing options, but right now open box for lower priced toys is the best for Transformers brand.