To my students who don't understand the expressions I make

                I’ve lost count of how many clay students had to restart all or part of their projects the past week, and subsequently how many times I’ve tried to stifle laughter.
                I found a way to make googling pictures of cartoon characters at work acceptable. Every week I have my students track their progress for me through a document like this:

                That was a week ago, with 9 kids professing they were doing good. As of today at least 3 projects from that class were completely destroyed and another is missing a piece. Stifling laughter is a surprisingly hard part of teaching high schoolers. One of them caught me laughing and decided it was worth proclaiming out loud. Oops... At least they’ve all made progress and are doing better than this class was 3 weeks ago:

I'm sure students notice my expression at times, but I fear they don't understand them, so I must say this to my students:

                 I don’t laugh because you made a mistake and it shows your lack of knowledge or the fact that I know you weren’t paying attention in class.  I laugh because your expressions are so funny.  I laugh and more-so just smile because I know that sometimes you are truly learning in that moment…or I smile because it’s the first time I’ve seen you really care about something…or because it’s the first time I’ve seen you stop and truly contemplate what you’ve learned and that you are problem solving on your own.  I also smile when you make the decision to restart your project not because it was falling apart, but because you want to do better.  Or I just laugh because you are annoying and restarting means you have to work harder and you know you can’t afford to waste time, thus you are FINALLY quiet.  I know you can’t all be wonderful, but I hope someday you will be.
                Not too many students seem to get upset when they have to start over…but sometimes they do.  In those moments I frown, perhaps too noticeably.  Another note to my students: I don’t frown because I'm unhappy with you, or if you are doing poorly or because your project won’t be due on time.  I frown because you frown, because you are upset and frustrated and I wish you weren’t.