CDN : Automatic when updating, adding images?

So I have a few sites hosted at Webflow.

On the newest of the two I was prompted, in Webflow, to optimize the images for all devices, etc. the power of the CDN. Did that and all is good.

My question is I don’t remember doing this on the “first site” I hosted/launched?

Is the CDN applied to “.IO” sites or only paid hosting versions?

Should I just assume this is being done atomically with the new images? If you optimize once, does that work moving forward, even if you swap out and add images to the site?

Any insights are much appreciated…and thanks!

Maybe this topic will clear it up.

Really? Wow.

It “did” as I said on the new site (about 2 weeks old) prompt me in Webflow. Said it would take several minutes, etc. Was even a link out explaining Webflows CDN advantage