That central button with the car with brackets underneath is used when the adaptive cruise control is on, it selects one of 5 distances for you to follow the car in front.
Either press it 5 times to cycle through the distances (which can be seen on the grey logo that appears when ACC is active) or press it once and use the controls to the left and right to increase / decrease the distance.
It is boring I know, but the car manual has tonnes of info such as this and without knowing the features you can be unaware of useful things the car can do. The manuals are available online.
For instance, the rocker to the L + R of the button normally selects the ACC target speed in 5mph increments, but not everyone knows that you can fine tune it by using the RES and SET buttins to change the target speed by +- 1mph.
Also in the mode settings (the button by the gear lever) if in individual mode, you can select how aggressive the ACC is in maintaining the selected speed. I have everything on sport mode except that (and engine artifical sound), as the ACC really surges to keep the speed eg when a slower car pulls over.