One would say about this idea, “What a pity I haven't hit upon it earlier!”
Footwear designer from Great Britain Helen Richard invented a method to help ladies get rid of annoying bags. Especially those who follow youth fashion.
Platform shoes that won long-lived popularity provide a considerable spatial resource. It is not necessary to make the platform monolithic. Modern materials allow creating sufficient rigidity even if there is a cavity inside the platform (the cavity serves to decrease the shoe's weight). But why should this cavity be wasted? Miss Richard designed a number of models where the cavity in the platform is used as a depository for necessary little things. You could reach the cavity through a special cover-door in the lateral part of the platform. But we think there are many other solutions and infinite possibilities for designer's endeavors.
Or Helen has seen too many spy films?
A bag and shoes have convolved into one object having two functions. In addition, the well-known TRIZ principle “Nested doll” is used here.

The source of information: “Technics for young people”.