When you see everything as Hitler no one will care when one such as him finally takes power.
When it comes to Der Spiegel I would not say that is fair statement. But question is from what you known that somebody like Hitler has taken the power? If you look how he rose to power you will have hard time to differentiate him from lot of politicians. He campaigned with German first platform, protectionism, national security, jobs for Germans, resign from "unfair" international agreements, stopping terrorizing minorities, stopping minorities stealing German jobs, Christian and family values, and so on.
Well, except for the whole Mein Kampf thing, being in prison for an attempted coup, and brown-shirted nazi thugs running riot in the streets.
Their rhetoric seems to come from this kind views, meaning views that saw Muslims as people who like behead people, so they put Trump beheading The Liberty, in order to put America first. Meaning that it isn't ironic coincidence but purposefully chosen rhetoric in order to use people's preconceptions to drive their message home (not saying that it works necessary well, but that seems to be intention behind their cover picture).
Intentional can still be ironic though.
Trump's travel moratorium approved for legality by DOJ: https://twitter.com/AriMelber/status/827304853353484288