Question

The storm lasted as long as it takes rice to cook” is an example of

Answer 1

I believe this is an example of a metaphor or using an expression which does not literally relate to the subject at hand although in this case we know that in a rice cooker it takes only about 20 minutes to cook the rice so though cooking rice and a storm do not normally relate to each other, in the time aspect they may relate. 

Answer 2

The storm lasted as long as it takes rice to cook” is an example of:
"Event Time"
This is a beautiful example and often is used to explain the length of an event as cooking of rice is a metaphor used that it can take hours or vary in its duration so does the storm.