Burgopak Ltd. and Uber Agency teamed up to create these invites for the BAFTA awards. Of the invites, they say:

Packaging design company Burgopak incorporated
their patented ‘slider’ mechanism into the design, providing a smart
and distinctive package to accompany the guests. The simple sliding
tray action reveals the invitation, with artwork designed by Uber. In
a classic and elegant approach, the design features the iconic BAFTA
masks on both white and black packages.