This is Farfugium japonicum 'Giganteum' (Giant Leopard Plant). Likes shade, but some sun during day. Adding this to my yard right away!
This window box has some really great features.
The Lechuza Balconera Cottage Self Watering Window Box is rustproof, weatherproof, hangs from walls or rails + can be floor planter, has pull-out liner making switching plantings easy, and a water reservoir to extend time between feedings. Window boxes dry out QUICKLY, so this is nice because you can monitor the reservoir levels as well on its indicator. The list of pros go on for this planter.
This is Farfugium japonicum 'Giganteum' (Giant Leopard Plant) in the round leaf.