You won't be able to dismiss this by usual means (escape or click button), but you can close it programatically based on user choices or actions.
"This is a really classy thank you note. I had people I wrote a thank you note to thanking me for the beautiful thank you."
"This matches the invitations and the RSVPs and is a great way to say thanks to your guests for coming to your special day! I put our picture on the back too!"
"I purchased these for my thank-you cards for my bridal shower as EVERYTHING had to be perfect and these were simply beautiful. Simple, sweet and elegant they fit the theme of our wedding beautifully. I received so many compliments on these cards and would purchase them again and again Thank you!"