This is a cloche. Cloche means bell in French. I believe a cloche was originally referred to as a small glass dome used to force plants to bloom (like a mini green house). But in decor terms, it's usually a display (raised on a stand) under glass.
Looking for a wedding theme? Try love birds! This is a creative and unhacked theme, actual for any season. How to rock this theme? There are hundreds of ideas, from love birds cake toppers to origami cranes as a wedding backdrop.