Yes, those tik tik what you hear are the lens. They moving forward and back, I think around max a 1mm, the system is electromagnetic to let them move forward and back to get focus, zoom some kind of stuff like that.
I don't remember if the system working exactly like that but close.
Mystery solved as I have it too, all we have, who don't have it do not have good ears..lol..
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My Evolution: Sony Xperia Z1 - UB + 4.3 Rooted + Deodexed, HTC HD2, HTC Diamond 2, HTC HD Blackstone, Nokia 7070 Prism, Qtek 9100, Nokia 3100, Motorola T720i, Nokia 3310, Sony Ericson PF 768 (Blue)
How Get Root on Sony Xperia Z1 with Locked Bootloader and the Latest Android 4.4