In Service Studio you can expose Themes owned by your eSpace (or main eSpace of an application) to be used by others. In this context, eSpaces are called Producer and Consumer, respectively.
This feature could help you, for example, to isolate and share company portal and image elements in a single eSpace.
In a Producer eSpace, set the Public property of your theme to Yes and publish the eSpace.
You cannot expose a theme of your eSpace when:
Your eSpace is multi-tenant;
Your theme has a web block with a link - screen reference, Link widget, or Button widget - with arguments of data type Binary Data, Record, or List.
In these situations, an error message is presented and the eSpace is not valid.
Use Theme References | About Themes | Theme Properties