In the "Instructions For Postal Duty", the corridor leading from the Guildhall's Entrance to the Library was to have seven uniformed telegraph messengers to distribute programmes and leaflets. Perhaps the above was one of the leaflets so mentioned. It's not mentioned in any of the texts yet seen about the Celebration at the Guildhall.
My copy of the announcement is on coarse laid paper, clean cut except for the bottom, which has a rough edge, perhaps being torn or from a worn 'deckle edge'? The illustration has been cropped.