The DES dark matter map is not the first of its kind. Several pioneering analyses have come before it, most notably the Canada-France-Hawaii Telescope Lensing Survey, which used 4 times the number of distant galaxies that DES used to map an area of similar size but at higher resolution. The two teams have reached the same conclusions, though: The luminous matter that we can see is housed within the dark matter structures that we cannot see, and this dark matter forms a cosmic web of filaments, knots, and voids. As it continues collecting and analyzing data, DES will be able to map how these dark matter structures evolve over time.
There's a lot more to be discovered here as more of the data are analyzed.