Need Opinions

Tonight's dilemma ... Can a sleep shirt be worn outside?  I purchased this item on sale at Target ($7.50!) today, and although it's technically a sleep shirt, it is just too cute!  I think it makes a nice little dress with a belt.  What do you think?  Sleep shirt only or dress too?

Xhilaration Blue Hearts Sleepshirt

It's a small heart print in mint green on blue with mint trims.  It's much longer on me, almost to my knees.  You can't really see it, but it has elastic sewn inside under the bust to add to the shape.  As a dress, how would you style it?