I'm not sure. It used to be that you could just select whatever as long as you do it with a mouse (so have human-like cursor movement). But latetly reCaptcha and hCaptcha have both been yelling loudly every time I didn't select one square that had a car or staircase or whatever it makes your look for even if that object is relatively small and easy to miss.

I think this is because the primary purpose of the excersise is AI training though.