I came across this quotation on page 145 of National Geographic Stunning Photographs. Google retrieved at least 100 results for it. Gunnar Nordstrom Gallery
Two particular works to be exhibited share historical similarities as well as juxtaposed iconography by two different Spanish artists. The first by Pablo Picasso is from 1922 and is a lovely dry point etching "Femme au Miroir" or "Woman looking onto a Mirror". Sitting nude, but reserved (much different than later works by Picasso also on display) a woman holds a mirror and gazes into it daydreaming of beauty, fashion and the future. Picasso said, "The hidden harmony is better than the obvious" as evident in this jewel of a print.
But this S.E. user couldn't find the primary source.
This may be a case where challenging the authenticity of the statement would have been appropriate. All sources I find for this post date publication in a 'quote book' in 2001, and the original can be linked to Heraclitus "a hidden harmony is better than an apparent one." quite a while before Picasso. – justCal
Did Picasso actually say this?