This paper proposes a new concept and mechanism for the user and content interaction between multiple spaces in a 3D virtual environment. We introduce two types of visual components; a flat, window-like WorldMirror, and a volumetric WorldBottle. These components embed other spaces inside and render them on their surface, so that users can look into the contents of other spaces from their current working one and choose to enter. They also allow content manipulation in embedded spaces from the current space. Users can move an object from an embedded space to the current working space, or drop an object from the current space into an embedded space. In contrast to conventional approaches, the proposed mechanism enables us not only to define a spatial connection between different spaces, but also to define a functional linkage among components in different spaces.