It lacks connection to it's environment. It should be connected with some shrubs at the corners instead of the posts with plants in pots. Also...does it need to sit with lawn all around it? It would be more mysterious if you brought shrubs and groundcover out to connect with it in an arc from the planters adjacent to it.

HI -- Maybe a surrounding deck and front stairs would help. The stepping stone looks like an awkward step for children . It is sitting up high so more plantings around might hide the space underneath.

Generally kids like color & movement. Maybe some steps & handles too to make getting in & out easier for little hands & feet. A small, colorful wind chime? Free flowing fabric to dance about in the wind? A faux steering wheel bolted on so they can steer their time machine?

How sweet this is! The girls might like getting involved, at this point. I think a board is needed so they can name their new retreat and paint a welcome sign for it. Gauze curtains for the windows hung on a long stick would be nice (helps keep bugs out,too), and some colours for the flower pots to go with it all. Birdbaths make another fun project to do together (or buy), and a feeder will bring more friends to the party. Of course, once you do that, a miniature cubby for their new friends seems only right! (with their own tiny steering wheel?)

So cute. I love the free flowing/gauze curtain ideas, and the front steps too. Maybe window boxes with easy to care for flowers, and a mailbox so you can leave them special messages?