Oppo's under-display camera is now official, here's how it works

A recent teaser showing an Oppo phone with the front camera completely hidden under the display piqued our interest: Could the Chinese company be the first to launch a smartphone that's all screen on the front, without any clumsy solutions such as notches or pop-up cameras?
Now, at MWC Shanghai, Oppo has officially unveiled its under-display camera tech, and while it certainly looks interesting, some questions remain. 
Oppo calls the technology USC (short for Under-Screen Camera), and claim