Yves Saint Laurent has referenced Mondrian directly by imitating the print within the confines of the most simple shift dress, so the focus is not on the silhouette, but the lines of the artwork. Although he actually constructed the dress in panels, we do not percieve them as panelling, but rather as a graphic design
Jump forward four decades to Elie Saab's fall 2008 collection, and we can see Mondrian's iconic paintings referanced and conceptualised in a further developed aesthetic. Saab's dresses are like quotations of mondrian. The recognisable blocks of primary colour, and black lines against a white background are apparent, but then manipulated in different ways to compliment the shape of the garment. The result: more of a subtle nod to Mondrian, as opposed to a full embrace.
If we step back for a moment and look at the differing approaches in context, each designers work makes perfect sense - they are a product of their times. The YSL dress is an artefact of the pop-art era (or at least the tail end when concepts started to filter through to fashion). YSL has placed an image from the "neo-plasticism" movement out of context, and as a result commercialised what would be considered abstract art
Mondrian, Composition with Yellow, Blue and Red. 1921.
Saab however is designing in an era of postmodernism where appropriation is the name of the game. I'm a little hesitant to use the word "postmodernism" in reference to art as it goes well beyond my understanding. So i'll leave that train of thought there.
So Centine, I haven't actually answered your question at all...might have to tackle that one another day with a less frazzled brain. But thanks for listening to my uneducated ramblings!
images from flickr.com, style.com, wikipedia.org