Xiaomi's Mi 6 flagship has a Qualcomm Snapdragon 835 processor powering it, but if a recent result on GFXBench is any indication, its sequel will actually get a downgrade to the Snapdragon 820 chip that powered most of 2016's flagship devices. A device showing the name Xiaomi Mi 7 is listed on the site, and shows all the usual hallmarks of a Xiaomi device. The device in question is running Android 7.0 (Nougat) on top of MIUI, which would mean that it's running MIUI 9, which began getting developer preview builds recently. The Snapdragon 820 inside it claims that it is only clocked to 1.6GHz for the test, which could mean that only the four low-power cores are in use, and is paired up with 3GB of RAM and 64GB of internal storage.
The Snapdragon 820 processor inside the device jumps around on the graphics table as far as scores go. As can be seen in the attached image, the device outscores Snapdragon 820-powered contemporaries like the Galaxy S7 and HTC 10 in some tests, falls flat in others, and is strangely unable to perform some of the tests. The compute section of the test, however, is missing entirely. The device seen here also has a 5.1-inch display with a 1080p resolution, a 15-megapixel back camera, and a 5-megapixel front camera. The usual bevy of sensors and interfaces is on board, and there is no heart rate monitor or thermometer.
Since the device shown here is a clear downgrade from the Xiaomi Mi 6, it's quite unlikely that this is actually the Xiaomi Mi 7. It could possibly be a dummy device for testing MIUI 9, since it is shown to be running Nougat under MIUI, or it could be an earlier Snapdragon 820 device with the new software on it, such as the Xiaomi Mi 5. It could even be a non-Xiaomi device with an MIUI custom ROM on it. These scenarios aren't too much of a stretch; it takes a simple edit to one system file to fake your phone's device name for a benchmark, and a tool called PatchROM makes it easy to patch MIUI over almost any AOSP-based custom ROM. In summation, what's on show here may be the Xiaomi Mi 5 with a software update, it may be a different phone entirely pretending to be the Xiaomi Mi 7, or it could be an internal dummy device used by Xiaomi for testing, but whatever it is, the likelihood of it being the actual Xiaomi Mi 7 is extremely low.