This image was uploaded five days after this highway accident:

Police arrest bus company president for involvement in fatal highway crash - The Japan Daily Press

• http://japandailypress.com/police-arrest-bus-company-president-for-involvement-in-fatal-highway-crash-282801

”The driver, Kazan Kono, admitted to police that he dozed off behind the wheel, and was charged with homicide as a result of negligent driving.”

So Reimu dozed off while fighting with Cirno?

For a second I thought this was actually a joke on the Comercial for "Paper Mario" (First one) where he swims in that same manner