Hello,
I have bought 5 iPhone 5c's for my family. 2 blue, 1 yellow, 1 green, and 1 pink. So far just our 2 blue iPhone 5c's have a glass clicking issue. Though the other ones seem to give a little at the middle right and left, but do not click.
The ones that have this problem do not do it all the time, but when it does, the glass will make a clicking sound on the middle left and/or middle right part of the glass. Sometimes the LCD shows pressure with liquid being push to the left or right where you press. You can feel the glass move up and down (as minute as it is). At first I thought, wow this glass feels soft! I have had hardwood flooring that does the same thing and the "softness" or "give" usually means there is an air pocket underneath certain parts. In this case the non-reinforced areas are most likely the middle-left and middle-right parts of the screen.
This problem can come and go. Might be hard to video as it is so minute. It is like the glue sticks for awhile and then refuses to stick in certain areas. The glass contorts and flexes. The steel corners obviously do not move but the gorilla glass does. My guess is the middle left and right are the weakest parts of the screen where it has the least support, the glass will flex there and the glass may contort slightly at the corners creating this popping effects.
By now with the Gen 5 style size screens, Apple should have put something in the middle left and middle right areas to re-enforce the steel frame in those areas to help keep everything level to prevent this unnecessary problem.
I have my Appt. at the AppleStore Sunday Oct 26. 2013 11am South Park. Hoping for a hassle free day.