https://www.techradar.com/news/oneplus-6-leak-points-to-a-snapdragon-845-and-a-notch

Following a recent leak that seemingly showed the OnePlus 6 in the flesh there's now further evidence that the phone will have a notch in the screen, as a pair of screenshots seemingly taken from a OnePlus 6 handset have also now leaked.

Obtained by Android Central from a "source close to OnePlus", the screenshots are in a 19:9 aspect ratio, which would mean the screen they're taken on is long and narrow, as has become trendy in the last year or so.