wifi antenna shield and logic board fork, what is the use?

Hi!

Can anyone tell me what is the use of the fork beneath the yellow screw seen in this photo? http://guide-images.ifixit.net/igi/diPxJ...

While replacing my home button flex I found out that the phone was opened before as the yellow screw holder is no longer soldered to the logic board (as it should be I think). There is also a fork above it, that makes contact with the shield when the screw is tightened. Now, the phone works, but I was curious what is the use of this screw assembly, because I managed to put it back so seemingly all parts make contact, but I can't tighten the screw completely. Can it damage something? Can I fix it somehow so the whole thing stays in place, without soldering?

Thank you in advance.