We went to 7-Eleven in Hong Kong. Felix had his phone pressed tightly into a sandwich box. He asked the clerk for help with removing the phone. Of course it was a joke, but the clerk could not tell from our facial expressions because we were wearing facemasks. The situation was embarrassing rather than funny. That’s why we created MojiMask, a mask that scans your mouth and visualizes your mood on a small display. The unit is reusable. It can be attached to standard off-the-shelf masks.