Bizarre feedback on performance

This is to bring into notice that I have been given sone weird feedback just bcoz the manager feels I look too serious on calls. Is it fair by company management to judge their resources on facial expressions. People work to deliver good code n support the team. Why can't they look at metrics n do the review based on actual work. We have been working long hours n weekends till this Wednesday already. But asking us to fake a smile is just too much. LEADERSHIP SERIOUSLY NEEDS A BETTER MINDSET!!!