What's the different between ([@weather]) and (@weather)?

before do
@weather = mock_model(Weather)
Weather.stub!(:find).and_return([@weather])
end

I saw this code on peepcode, but I’m a little confused the
and_return([@weather]).
mostly, we just and_return(@weather), don’t we? so, what is the meaning
of and_return([@weather]) ?