I see a notice board well decorated with coloured papers. On the board it is written, " Did you smile today ? "
I feel the prompt is trying to know how we feel and our mood.
This sounds like a question that one of my friend will just ask you randomly to check if you are fine. The other day she drop a message " Sir are you happy ? " and I smiled 馃ぃ. I think that's the same thing the prompt is trying to ask.