This outrageous combination is pretty much textbook pattern mixing. Notice that in the three elements of this outfit (suit, shirt, tie) each part varies – the type (plaid, stripe, graphic), color (tan, blue, red) and scale (small, medium, large). The essential rule of pattern mixing is not to put like with like, but rather to mix unlike but complementary elements. The only close call here is the vertical stripes and the vertical element of the plaid, but color makes up for that.
Would I wear this combo? Probably not. I’d have grabbed a solid shirt. But is this reasonably successful? Yes.