Has anyone seen Reiss emails on mobile, they have a navigation that drop downs... How are they doing? - didnt think possible on email, wonder how many email clients this works in?

https://email.reiss.com/pub/sf/FormLink?_ri_=X0Gzc2X%3DYQpglLjHJlTQGu5EzchPWNfLEazgDzfXmzcJKAFJzarLRTNzap4tszeBW0pSyPzdlr6tVXMtX%3DYQpglLjHJlTQGszgzclJzeOpPRzecbUvq0vnvPStze3F5csp5NNMum7ze1P60i6Gzba&_ei_=EolaGGF4SNMvxFF7KucKuWOmmFstRNJbrQdBdklDGA54GVzoaOrIFzTSptJHN5jqDJ7cfuaxFT3S6ybjuMo.

Anyone know?

The menu

The drop down

Upstate