The wings in a proscenium theatre serve as:

1. Aesthetic element: The wings are part of the stage design and contribute to the overall visual appeal of the production by creating the desired atmosphere and setting.

2. Concealment area: The wings provide a space for actors, props, and set pieces to be hidden from the audience's view until they are needed onstage. This allows for quick and seamless scene changes.

3. Storage space: The wings often have storage areas or racks where costumes, props, and other production elements can be stored within easy reach of the stage.

4. Performance area: In some productions, the wings may be used as an extended performance space. Actors can enter and exit the stage from the wings, allowing for more dynamic movement and staging.

5. Technical area: The wings can house various technical elements like lighting fixtures, sound equipment, and stage machinery. This allows for efficient operation and control during the performance.

6. Safety zone: The wings provide a safe area for performers to wait, rest, or prepare for their next entrance. They can also be used to keep performers hidden during blackout moments or scene changes to ensure their safety.

Overall, the wings in a proscenium theatre serve multiple purposes, combining functionality, aesthetics, and practicality to support the smooth execution of a production.