As best as I can describe it, the wiper linkage is like an old "choo-choo" train. The motor goes around in a circle & so does the first little short arm bolted to it, but the long arms that go to each wiper pivot sort of move like the arms you see going to the wheels on a "choo-choo"....sort of like it's reversed in that the wiper pivot end of the long arms is similar to the choo-choo drive piston & the wiper motor is like the choo-choo wheel (powered opposite vs. a choo-choo)

I like typing "choo-choo"