Photos of the LG G3 cases have recently made an appearance on AliExpress, hinting at what could be the phone’s back cover design. This follows a series of leaks related to the G3 that have revealed many of the phone’s specs and UI features.

The case design shows a similar design to the LG G2, with an oblong opening most likely dedicated to the camera lens, power, and volume buttons. LG is sticking with the back button design previously used on many of its devices, and that’s a good thing — I am personally a fan of this design and I am not the only one.

However, the mysterious part of the case is the presence of two small openings next to this main vertical one. These are horizontally aligned and leave us a bit perplex. The G2 as well as the G Pro had one single element on the back next to the camera, and it was the LED flash. It remains to be determined what new element is on the opposite side on the G2. Possible options include:

• a second LED flash: a likely option though not essential if LG includes OIS on the G3 (which is almost a certainty)
• a heart rate monitor: a doubtful addition considering that not a single leak has mentioned this yet
• a fingerprint reader: a very unlikely option given the size of the opening and LG’s push for Knock Code as a security measure for its phones
• a microphone hole: a possible option though not very likely given that these tend to be smaller. However, some variants of the G2 had a microphone hole next to the LED flash, so LG might have moved it to the opposing side.
• another mysterious sensor or option.

To be honest, this new design leaves me scratching my head, as no possibility seems to fit really well. I’m also a bit annoyed, I like the skewed design of the G2 and this cross-like opening is too symmetric for my liking.

What do you think this new opening is for? Are you leaning toward any of the options I mentioned here or do you have other doubts and suspicions?