Google's Chrome 85 has lots of new bells and whistles. One I've been playing with is Tab Hover Cards.
Although I have Chrome 85, this specific feature is not enabled. Google tends to roll these out in waves.
If you want to see it now, go to chrome://flags and search for "tab-hover-card". I intentionally omitted the "s" at the end so you'll see both flags.
For each entry, click on the blue box and change the setting to "Enabled".
"Tab Hover Cards" has choices for "Enabled", "Enabled B", and "Enabled C". These affect how quickly the preview pops up.
Then you'll need to relaunch Chrome.
This is what the preview looks like.