Board Thread:Wiki-Related Discussion/@comment-91424-20160807191405/@comment-91424-20160808004140

You know what, I think the book I linked to, may have been too strict. I found this one the website of a production designer who worked on Battlestar Galactica:

"The difference between a set decoration and a prop is use. If the item is not touched by an actor for any reason it is simply a set decoration. Some set dec, such as a chair or table, can be touched by actors but would still be set decoration."

Which means that MM's cup IS a prop.