Interesting pic, but be careful of assuming that the low pressure region is directly proportional to lift. The fuselage is relatively long chord, so a much lower pressure drop will, integrated over the longer "chord", create proportionately more lift. But, yes, the diagram of the SEP is over simplified - usually a fuselage degrades lift compared to the isolated wing.
I think the cloud over the wing shows an "3D iso-presure-surface", you are right it says nothing over a mayby slower lift above or below the fuselage, but it shows that in this case, the lift over the inner part of the wing is reduced