To add to my last comment.... the main bar is bright/light where the upper part of the square bits is very dark....the sort of thing that implies they are hollow and thus in shadow...though the lower part of of the square bits is dark - matching the lower edge of the main bar and is thus equally convex....so the overall lighting of the square bits are confusing - in conflict.
The 'solution' is to lighten the top shadow section of the square bits...to reinforce the appearance/representation of a convex form.
The only real time you can have that effect of altered shadow is if the square bits are themselves self-lit and forcing a shadow change... like you get with glass/chrome reflections, etc. Then you get 'hard'/dark sections in 'odd' places....
