The "dashboard" is petstore's initial screen. It appears because userStart.inq, the script returned by the client login sequence, amongst other things includes this:
// Load the gui elements of petstore loadclient("userMain.inq"); . .
The dashboard GUI is implemented in gui/userMain.inq.
The dashboard GUI is a simple layout of buttons. Their properties are configured, a layout performed and event handlers attached. The Table Layout is used. For further details see on using table layout see the Inq Mini Guide.
The dashboard looks like this: