I like the message here and you worded it in such a delicate way which is quite beautiful :)
Caging a heart is like caging a bird. When stuck behind cold metal it loses its ambition and kinda loses its spark, the drive to keep on. Visions of flying fade from its eyes.
But cupping it gives it the ability to take flight when it feels like it, to spread its wings and bask in the beauty of the earth. It's beautiful.
I love how you give a heart emotions like a person. Nice way to personify something that holds so much in a body.