Venetian masks are a centuries-old tradition of Venice, Italy. The masks are typically worn during the Carnival (Carnival of Venice), but have been used on many other occasions in the past, usually as a device for hiding the wearer's identity and social status. The mask would permit the wearer to act more freely in cases where he or she wanted to interact with other members of the society outside the bounds of identity and everyday convention. It was useful for a variety of purposes, some of them illicit or criminal, others just personal, such as romantic encounters.
This is a miniature mask displayed in the window of a shop at via Po
Venetian masks are characterised by their ornate design, featuring bright colours such as gold or silver and the use of complex decorations in the baroque style. Many designs of Venetian masks stem from Commedia dell'arte. They can be full-face masks (e.g. the bauta) or eye masks (e.g. the Columbina).
(Text quoted from : http://themascherade.com/contents/en-us/d5_Page_5.html )