In the teacher dashboard, screens where students can graph using the Desmos Graphing Calculator will show up in two different forms in the teacher dashboard.
Thumbs Mode refers to the view of all the separate student answers to a graphing question. Simply click on a screen that has a graph answers and the default view will be in Thumbs Mode. To see more details about a student's answer, click on their graph.
Overlay Mode refers to the view of all student answers on the same graph. To show this view, simply click on "Overlay". The opacity of the graph indicates how prevalent a response was. For example, the darker a line appears, the more students that graphed it on their individual screens.
If the original question already had components graphed on it, these will also appear in the Overlay. To turn it off and only see what students added to their graphs, you can uncheck "Show Original".