Aside from a few headlining features, Apple focused on improving things in iOS 12. Rather than reworking the functionality left and right and risking a mess like iOS 11, this year's features are smaller. For example, you can now display favicons in Safari – nothing groundbreaking, but a nice touch.
If you've been using a desktop browser, you're probably familiar with favicons. It's the little website icons that appear next to the title of a page in the tab bar. They are available in other iOS browsers, such as Chrome and Firefox, and the same icons are used on the Favorites screen in Safari. Now you can add them to Safari's Tab Switcher interface on your iPhone.
It's really easy. As long as you run iOS 1
The changes take effect immediately, so you do not have to restart Safari or reload pages , Just go to the tab menu and to the right of the little "X" will be the favicon of the page.
Sure, it is a small improvement, but it definitely makes the tab menu much nicer. If you have a set of tabs open, it should be easier to find what you are looking for.