Real national output increases from $Y_1$ to $Y_2$ with no change in the price level because the economy is operating with significant spare capacity, allowing firms to increase production without bidding up wages or resource prices.

The shift from $A{D}_1$ to $A{D}_2$ is purely inflationary because any increase in aggregate demand must immediately bid up wages and resource prices due to a lack of spare capacity.

Real output increases to $Y_2$ but this is unsustainable in the long run because wages will automatically adjust downwards to return the economy to its natural rate of output at $Y_1$.

The expansion in aggregate demand is immediately offset by a leftward contraction in aggregate supply because of crowding-out in the financial sector.