...
The panel behaves like any other InDesign Panel. It can be docked, connected to other panels or float on its own.
  |   |  |
User interface
...
When the check box is activated, the selected frame(s) will be proportionally scaled when adapting. The prerequisite for this is that the selected frame is allocated to three frame edge tools.
...
Note
For proportional size you use two tools of Dylation on opposite edges of the frame.
Frame Type
The upper right icon will give you a visual representation of the frame type.
...