Why does "der Suppe" translate to "that soup" and not "the soup"?
Der can be translated as either the or that, I think. It might be an error in the platform. You can always suggest!
The more interesting question is: Why the hack is the shoe in the soup?
Because soup is feminine, so it should be "die Suppe" unless you are using the dative form, in which case "der" is the female article. Almost all words ending in e are feminine.