Open it
In the composer, click the bookmark button, Your saved elements. The window has four tabs: All, Characters, Places and Objects.
Characters
Characters are the avatars saved for this store. Pick one and it is attached to the composer as a reference, next to any image you already dropped. It is not pasted into your prompt: write the prompt as usual and refer to the person in it.
Places and Objects
These two tabs are empty for now, and they say so. There is nothing to save into them yet. They are visible so the window does not change shape the day they open.
Good to know
A saved element is a file stored with your store. It can be used by anyone who can generate on this store, and only on this store.