what does "metaphor" mean in this sentence?

For the best part of a week, the Suez canal was blocked by a 200,000­tonne metaphor.The Ever Given is not just one of the world’s biggest container ships, it is also the emblem of a backlash that accuses globalisation of going too far. Since the early 1990s supply chains have been run to maximise efficiency. Firms have sought to specialise and to concentrate particular tasks in places that offer economies of scale. Now, however, there are growing worries that, like a ship which is too big to steer, supply chains have become a source of vulnerability.

As far as I know, metaphor is a figure of speech that is used to make a comparision between two things that aren’t alike but do have something in common.But it seems like a name of ship in this sentence.
Thank you for your help.