crwdns2933897:0crwdne2933897:0

What is this plastic element?

Does anyone know what this plastic piece with the white squares is for? I noticed it was missing while assembling the phone, and everything works fine once it's assembled, so it's apparently not necessary, but what is its purpose?

crwdns2915344:0crwdne2915344:0
crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2853045:0crwdne2853045:0 crwdns2853046:0crwdne2853046:0
crwdns2889612:0crwdne2889612:0 0
crwdns2934285:0crwdne2934285:0