Strange textures when using front cam or watching videod

[BlackD0127]

My sister got her iPhone 6 replaced and the new iPhone she got has some interesting bug. When using the front facing camera, the picture gets a strange texture.Example picture below.


This same problem appears sometimes while watching videos.
She brought it to an Apple-like Shop called MacShark (or something like that), they said it's a software issue, try reinstall the OS. After reinstallng it two times, the problem still appeared.
Has anyone got an idea what this problem is?

 

[Deanig_12]

you may need to visit apple store could be a faulty camera or the ribbon is not connected properly

 

[BlackD0127]

Okay, hopefully the won't send us this time home with telling us it's only a software issue