Topic on Talk:Grand Theft Auto IV
The "Xbox 360 emulator on an Xbox One" is just the weird Russian way of saying "I played the game through back-compat on my Xbox One" as there is no other X360 emu on the XOne other than the back-compat.
As for the settings, they are not that important for most of the comparisons, because if all the settings are at least medium (and I highly doubt the author of the comparison used lower settings, other than maybe night shadows) then all of the game's available graphical effects (that are there on PC) are in use, turning them up any further will only increase the clarity of the effects (or the amount of "wrinkles" in the water), the game will still look almost identical.
The settings are important only for the flickering comparison, because there are some rumors on the internet that if you change the view and detail distance to console-like settings there will be no flickering, because the game was designed for those values or something. I personally haven't looked into that. Also, the vast majority of PC helicopter gameplay on YT is gonna show flickering similar to the Russian comparison.
I myself have personally noticed that the vehicle reflections, volumetric lighting and rain are exactly as in the comparison (I play on all medium except high textures, no night shadows, 25 draw distance, 40 detail distance and 33 vehicle density).