Ok, something's wrong here. In those slider bars, it's quite clear that different shadow settings had been enabled in both FSR and DLSS. When you pass the slider over the rock in the middle of the screen the rock looks white if the shadow is absent or dark grey if the shadow is present. The shadow extends across the grass above so this is not an apples-to-apples comparison. You can't use a comparative slider bar when the two images have different graphics settings!
The shadow also has nothing to do with either FSR or DLSS because at 2160p the extra shadows are absent for Native and DLSS Quality but present for FSR Quality. Then, at 1440p they reverse and are only present for Native and DLSS Quality while absent for FSR Quality. After that, they're all over the place. The other bad aspect of this is the fact that with different shadow settings, the FPS comparisons aren't valid either. This article is one big dumpster fire because of this and I stopped reading it.
The optics of this make it appear that someone really wants to make DLSS Quality look more like native than FSR Quality at higher resolutions and are using the shadow settings to achieve that goal. Only at 1080p was this comparison done properly with the extra shadows not being there across the board. If I had done this graphic, I'd be embarrassed as hell and would've re-done it immediately because I would rather release an article a day late than release it on time with optics as bad as this.
Check for yourself:
2160p:
Native TAA - Shadow is absent
FSR Quality - Shadow is present
DLSS Quality - Shadow is absent
FSR Balanced - Shadow is present
DLSS Balanced - Shadow is absent
FSR Performance - Shadow is absent
DLSS Performance - Shadow is absent
FSR Ultra Performance - Shadow is present
DLSS Ultra Performance - Shadow is absent
1440p:
Native TAA - Shadow is present
FSR Quality - Shadow is absent
DLSS Quality - Shadow is present
FSR Balanced - Shadow is absent
DLSS Balanced - Shadow is absent
FSR Performance - Shadow is absent
DLSS Performance - Shadow is absent
This renders the entire comparison slider useless because the images weren't the same to begin with.