Ruby Koans - About Hashes - why breaking out the hash is necessary?

gistfile1.rb

  def test_changing_hashes
    hash = { :one => "uno", :two => "dos" }
    hash[:one] = "eins"

    expected = { :one => "eins", :two => "dos" }
    assert_equal true, expected == hash
    assert_equal true, { :one => "eins", :two => "dos" } == hash

    # Bonus Question: Why was "expected" broken out into a variable
    # rather than used as a literal?
  end