Iron my shirt?

I just read this news. It was a little bit funny. During the US president candidate rally of Hillary, two protesters hold the signboard and chanted "Iron my shirt".

What was the intention? Was it intended for an insult? Maybe. Judging from the scenario.

Usually, where you can find the iron my shirt campaign is only at home. Where the husband would shout.

You can use it in a romantic way also. When proposing for marriage, "would you like to iron my clothes?" Not sure whether you would fail or not ;)