What is the Detective magnifying glass?

The blue rosettes with a magnifying glass are League points, which determine if your team advances in league divisions and if you'll get more league prizes at the end of event. They can be earned by completing Help Wanted cases and competing in lounge competitions. To see your team points compared to the other teams with which you are grouped, enter the lounge and tap on the trophy icon. There you can also see the weekly prize (diamonds) for participants, see event prizes by tapping on the green magnifying glass next to the chest, and see your team ranked globally by tapping on the globe icon in the bottom left.