When I worked retail, I found that my customers would really like me a lot the more neutral I was, they would project their own ideas and beliefs onto me and assume I was in total agreement with them.
Which is all to say, it's okay to have restraint. Let the story do the acting and just keep your characters alive and involved, the audience will put the emotion into the character. You will never be able to sell heartbrokenness with movement and poses as well as if the story sets it up well and you give the audience a blank canvas to project their own experiences of heartbrokenness onto.
Course the trick is, how do you do this in a short demo reel clip? My friend Eric Luhta does it in his chosen one clip on his demo. And JHD does it in his looks clear exercise.
swiped this image from Dr. Glen Johnson's syllabus notes page, which looks like it might be useful to dig through the rest of