that is more of a computer graphic, so tough to tell...i would imagine (hope) that Toyota has engineered the location of the pivot, the shape of the windshield and the size of the blade to maximize clearing area...i would assume there are safety concerns to ensure the wipers clear enough of the visible area to ensure proper visibility...assuming it is designed properly, i would think that a single wiper would be effective at clearing the windshield...my Rio5 "drivers" wiper is also quite large, and the "passenger" wiper is a small "add on" to get that extra little bit...it isn't like the "old days" where you had two similar sized wipers, that's for sure...i'm not sure of the exact lengths, but if i were to guess, i would say the drivers is a 24 and the passenger is a 16 or something like (maybe 22 and 18, hard to tell)...a single wiper blade means no linkage and one blade...less complex (although, wiper set ups are pretty reliable anyway), but more importantly, cost savings...i would be more concerned about wiper performance than how many wipers it had, or any cost savings though...as long as the single wiper works fine (i imagine it does), i wouldn't care.