Well I can understand this feeling very well, sometimes you are sad and you Don't want to smile, but you smile because of its necessity. you try to hide your sadness, but those who are your real friends, judge it by just looking at your face. The girl in the picture is in the party and EVerybody is enjoying but you can clearly see sadness on her face, the sadness she was hiding from everyone, maybe she is tensed, There could be many reasons of it. @velimir you have very sharp eyes that you noticed it. I hope EVerything will be fine and soon or someday her every tension will be gone and we can see the smile on her face, smile the real smile, not the fake one. @velimir that is why I am your fan and you are a real artistic photographer. God bless you, @velimir sir.