Not really relevant anymore, almost everything is chromium nowadays and if you do responsive design in the first place the only thing you gotta test against is Firefox and maybe in some rare cases Safari on a 2 generation old iPad. The rest just works ™
What this meme originally alluded to is the time where it was rather common to check useragent on initial request and serve a completely different site, HTML, CSS, and everything, based on which device you visit from. So you'd have like a site for Chrome, and for Opera, for Firefox, for Edge and every IE, a Mac version, one for iPad, and a separate version for each iPhone model following the everchanging style guides, also a WAP site, a site for playstation, xbox and wii, and also a few Android ones. But the only company I know that still does this is Google, who serves a broken version of it's search to mobile Firefox users, just because they can.