To begin, the striped shirt is juxtaposed against a checked jacket but the patterns are of different scales and work together. And the color of the shirt's stripe is picked up by the jacket's check even though the two are but distant relations rather than immediate family. Needless to say, the white of the shirt ground is enhanced by the pocket square of the same color (after all, the frequency with which white appears in shirts is what led to the ubiquity of the white linen square). The jacket's tan ground stands alone, relating to nothing above the waist (though viewed from afar I would not be surprised to see a pair of tan bluchers on the wearer's feet).
The secret to this combination is the necktie, in what appears to be gray wool or cashmere. Like the jacket's ground, the gray relates to nothing else above the waist, though it tones somewhat with the check. And because it relates to nothing, it gives the ensemble the air of ease that I mention so often.
It may have taken time to assemble the combination in the photo, but the result looks as though it took no time at all.