In Short: The OPPO R19 has surfaced on Weibo (Chinese social network), and this leak may actually indicate the design of the OnePlus 7. As you can see, the device is made out of metal, and it resembles the OPPO R17 (Pro) and upcoming OnePlus 6T quite a bit. There are two vertically-aligned cameras on the back, a power / lock button is included on the right, while the volume up / down buttons sit on the left. Bezels on this smartphone are almost non-existent, the phone does have an extremely thin 'chin' below the display, and instead of a teardrop notch at the top, there is a tiny cutout in the display itself for the phone's front-facing camera. That cutout is not connected to the top of the display, so we can't really say this is a notch or anything of the sort.
Background: Previous OnePlus devices have resembled OPPO's creations quite a bit, which is what leads us to believe the same will happen with the OPPO R19 and OnePlus 7. The OPPO R11 looked basically the same as the OnePlus 5, with the exception of the alert slider on the OnePlus 5. The same can be said for the OPPO R11s and OnePlus 5T, while there are not much difference between the OPPO R15 and OnePlus 6 either, save for a different placement o the rear-facing cameras. So, if this OPPO R19 leak is accurate, the OnePlus 7 will probably look like that when it gets announced next year, with the addition of an alert slider, of course.
Impact: The OPPO R19 is expected to arrive in the first quarter of next year, quite probably in March, as today's leak states. The OnePlus 7, on the other hand, will probably be announced in April or May, at least based on announcement dates of its predecessors. The OnePlus 7 is still a mystery at this point, which is not surprising considering that the OnePlus 6T hasn't been announced just yet, but it will be on October 30, as the company confirmed recently. The OnePlus 6T will sport a really small 'teardrop' notch at the top of the display, and aside from that, it will look almost identical to the leaked OPPO R19 handset. The OnePlus 6T shares most of its internals with the OnePlus 6, but it will bring some new features to the table, of course. The OnePlus 6T will sport an in-display fingerprint scanner, unlike the OnePlus 6, while it will also arrive with a larger display, and a larger battery as well. The OnePlus 7 will almost certainly ship with the next-gen flagship processor from Qualcomm, the rumored Snapdragon 8150 aka Snapdragon 855, and the device will probably include a similar display size to the upcoming OnePlus 6T, while we're expecting to see an OLED panel on the device yet again. OnePlus may improve fast charging for the OnePlus 7 even more, based on OPPO's Super VOOC Flash Charge, while Android 9 Pie will come pre-installed on the OnePlus 7 with a new version of OxygenOS on top of it.