https://www.cnet.com/news/oneplus-5t-sells-nov-21-499-face-unlock-dual-cameras/

While the last upgrade, from the OnePlus 3T to the OnePlus 5, was all about internal improvements (yes, they skipped the OnePlus 4), this transition to the 5T made some very noticeable changes to the phone's looks. It's taller, with slim bezels and a screen that takes up almost the whole phone face. 

There's also a shift on the camera strategy. Oh, don't worry, you'll still find two cameras on the rear -- they even keep the same megapixel proportions, 16 and 20 -- but the 20-megapixel telephoto lens now gives way to a low-light sensor. OnePlus is jumping on trends to emphasize portrait photography and low light. With these lenses, it especially takes aim at the iPhone (portrait prowess) and Google Pixel 2 (low light excellence).