I'm not educated in art, so I may be way off, but to me it seems like a difference in scope. Surrealism presents you will a completely surreal universe, while this presents you will a single surreal element in an otherwise realistic setting.

Magical Realism is the water turning into people wearing white clothes.

Surrealism is water turning into an army of ducks invading the kingdom of clocks made out of ice cream

Unrealism is water running uphill and turning into diamonds.

Too-Realism is water flooding an apartment and wrecking everything.

Hope that clears it up for ya.