I did this for the Seventh Sanctum Tarot Card Generator Contest here - [link]
I really liked the Tarot Card concept, and couldn't sleep. So I went to play with it again and came up with this on the early morning before the contest ended. So this may or may not be added among the judgeable cards, nonetheless. I had fun.
The interpretation from my perspective is this ( Though the beauty of Tarot is that it can be interpreted many ways )
A mask in of itself is much akin to a disguise, a way to keep a part of oneself hidden. Masks vary type, to type. One can be worn for an evening to get away.
But sometimes they are more discreet than a piece of flimsy cardboard, and often used to hide more than just the surface of ones face.
In the case of the Mask of Imprisonment, it can mean that you are a prisoner, locked behind a mask you have placed upon yourself, and what you are hiding may not necessarily be negative.
Hiding behind your fears, and grief, not quite ready to emerge from whatever haunts you, and move on with your life, to see the beauty around you.