Fold Geometries... do not trust what you see if you don't understand it.
The pictures on the left give access to the 3D geometry of the folds.  The picture on the top represents a 2D section through a fold.  On that section the fold seems to be sligtly overturn as the younging of one of its limb seems to be locally directed downward (see insert).  The picture underneath (bottom rigth) shows the same fold, but the picture was taken with a sligtly different orientation, actually you are looking parallel to the fold hinge.   On that picture there appear to have no overturned limb.  The lesson from this is that the true geometry of folds can only be read on plane perpendicular to the fold hinge.  Any other plane will give you an apparent geometry that can be extremely misleading.