Earlier this month, T-Mobile Galaxy S8s received an update that reportedly enabled Daydream, but Daydream was (and still is) incompatible. T-Mobile later updated its changelog to reflect this. However, Verizon hasn't learned from Team Magenta's mistake and is reporting Daydream support in their new update's changelog as well. But things you do get include an updated navigation bar (for better or for worse), as well as the ability to send GIFs during phone calls.
As far as Daydream support goes, we've already seen reports from Verizon S8 owners that the Daydream app still shows their phones as incompatible, so that's that. We still don't know what hasn't been enabled or who hasn't flipped a switch, but the fact of the matter is that no Galaxy S8s in consumer hands currently have Daydream support.
left: New color options. right: No more black nav bar.
Moving onto the navigation bar, it's the same thing that we saw with T-Mobile models about two weeks ago. Here's the gist of it: there are new pastel colors you can enable, and you can enable a little button on the bar to hide it at your will. However, I said it in the T-Mobile article and I'll say it again: do not choose a new background color if you're using the black nav bar and want to keep it black. You won't be able to go back, and I'm now stuck with an ugly white bar that sticks out like a sore thumb on predominantly black-themed apps like Spotify. Don't make the same mistakes that I did.
left: Dialer. middle: GIF selector, plus "Soojin Jeong." right: My phone trying to make me look like an idiot.
And lastly, you can now send GIFs during phone calls. Don't ask me why the capability exists, but it's there if you want it. I think the best part of this feature's announcement is that the person who took the screenshot forgot to change their name (Soojin Jeong) to Christina Adams above the GIF selection area. Also related: I have a T-Mobile S8+ on the latest update, and even though this GIF function doesn't show up in the changelog and I don't remember enabling anything, some missed calls made me send two of those potato GIFs to some guy I was texting about tires. He probably thought I was insane.
The update carries build numbers NRD90M.G950USQU1AQG4 and NRD90M.G955USQU1AQG4, and it should also bring the July 2017 security patch. It's already rolling out, so if you haven't received an update notification, now might be the time to head into your settings.