You can still get to the original image from the results without an extension.

If you select an image in the search results and right click on it, you can (in chrome at least) select "Open image in new tab" to get to the full image.

But that gives you a url-encoded version of the image, not the actual URL of it, IIRC, which is sometimes annoying.

Edit: It looks like they've changed it back to the actual URLs.

Yeah, that's what I thought too, but it does indeed look like they've changed it. The change is subtle, but results in not much changing for people that ultimately are just looking to grab a quick image for non-commercial purposes.

It gives a low resolution thumbnail of the image

That's what I thought too when a friend told me this, but if you click the image to open the larger preview and right click on it ("Open image in new tab", not "open link in new tab") it will open the original image.

Does not work on mobile.