The blocker depends on the EasyPrivacy Tracking Protection List, which covers a host of known tracker scripts. It's not automatically determining which trackers are the offensive ones.

There are some functional upgrades beyond this, we'd add. An upgraded Snapshot lets you save sites as PDFs, capture screenshots of the entire page and crop specific sections. You can add emojis, selfies and text, too. Although these aren't likely to win you over to Opera by themselves (Edge has had annotation for a while), they could be helpful if you like Opera's approach and regularly find yourself commenting on shared web links.