Not taking a jab at the graphics, but when I started watching the Gamexplain video, I legit thought I had the Youtube resolution settings on too low and tried to change it.
However, I forgot that this is handheld footage.
So it's 540p, which doesn't look good on a big PC monitor. It'll look better on a small screen like the Switch display. And in docked mode, it'll be sharper at 720p.
Haven't checked out Digital Foundry's analysis yet, but I wouldn't be surprised if they deem this the most ambitious/impressive port to Switch so far.