Using the curved outwards rear side of the blade will make it much less efficient whether the shroud is there or not.
Yeah but, in the photo, the convex side is to the radiator and the concave side is to the motor. i.e. on correctly.
Have another look at the photo, the motor turns clockwise from the front. If you reckon that fan is on the correct way you better have a look at the ones on your vehicles.
So, the fan is meant to be pushing the air out through the radiator. Is that what you are trying to say? In that case, turning the fan around won't make much difference. You'll have to change the angle on the blades.
Still looks ok to me, or they're all wrong.