These buttons are made to resemble keys from an old-fashioned typewriter.
The printing dress is the first piece of fashion technology by microsoft was entered at the International Symposium on Wearable Computers (ISWC) in San Francisco.
The dress was created by Microsofts Asta Roseway and Sheridan Marin Small who were exploring the idea of texting on the go--right on your very body. Having people wear their thoughts, the designers thought would create consequences. The communicator could no longer assume anonymity. If you "wear what you tweet", you might be a bit more careful. it might create more of a sense of accountability--if our words lingered on us.
In theory, the wearer could type a message on the buttons which would be displayed on the dress. However, the dress is not wearable,as it requires both a projector and laptop under the skirts.
For more information see the Microsoft Research website.