'The flowers were beautiful. Thank you!'
'My sister was thrilled, the flowers arrived in 2 hours after ordering. It was a lovely arrangement and I appreciated the help o received on the phone when ordering.'
'Suggestion - I would have loved to have seen a photo of the final delivery of flowers since I was unable to view them personally.'
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.