What's the thing I just broke in my phone???

[Trevor Phillips5]

Hi, so i bought new s5 mini and broke one tiny element even before I managed to turn it on. There is small plastic cover next to sim card. As I removed that plastic cover, this small element snapped right off. Thing is the phone works normally, I haven't tested all the functions yet but so far all good. Can someone tell me what it does and is it hard/expensive to fix? Made a red circle around it on a pic.

 

[Slashyou]

Hi, so i bought new s5 mini and broke one tiny element even before I managed to turn it on. There is small plastic cover next to sim card. As I removed that plastic cover, this small element snapped right off. Thing is the phone works normally, I haven't tested all the functions yet but so far all good. Can someone tell me what it does and is it hard/expensive to fix? Made a red circle around it on a pic.

Not sure the little gold thing is the antenna and the open flap is for the home button.