With nothing changed, it's a simple 45 degree line. Let's try the ShadowBoost curve. It brings up detail in shadows with very little influence on the highlights. Since the curve is all above the 45 degree line of the original, some exposure lift is seen throughout. Let's try the FilmLook2 curve.
Contrast goes down.
That happens when the slope is less than 45 degrees. Shadows are lifted and highlight detail is extended. The impression is that of extended dynamic range. Let's try the GammaLift curve. This brings the level of the shot up quite a bit.