Windows 10 1903 'Welcome to Windows'

Noel Burgess "This page, shown to all users upgrading to a version of Windows 10, doesn't look good in Dev 77.0.211.3 on my 1600 x 900 screen ..."

Very interesting.  The "https://www.msn.com/spartan/dhpwinfre?country=gb&locale=en-gb&imgh=170&imgw=300&bcnt=3&templatetype=1.1&placement=353689&useIris=1&tcContentId=a51e1cc323404b0782ddbdcdbf573894&tcContentPath=//item[0]&asid=a51e1cc323404b0782ddbdcdbf573894&poptin=&oemname=TOSHIBA&oemid=TOSHIBA&devfam=WINDOWS.DESKTOP&devosver=10.0.18362.239&ossku=PROFESSIONAL&arch=X64&cdmver=10.0.18362.1&fosver=14393&prevosver=16299&isu=0&tl=4&msa=&disphorzres=1600&dispvertres=900&nettype=WIFI&metered=FALSE&moid=&topt=&localid=w:F22B750D-657A-A8FA-2C4B-1D2C1E83FF40&auid=&lo=2080514&tsu=6&flsid=&osbuild=&waasring=&sc-sigimg=&OCID=ems.display.welcomeexperience&CCID=5B1EED13E2E645289FFD9242F65B9CDA&market=GB&enableregulatorypsm=0&enablecpsm=0&ishostisolationenforced=0&targetexperience=default&tabbedshell=0" page renders very differently in EdgeChromium, EdgeHTML (Edge Classic) and Firefox, including different graphics and different action buttons.   

If it was just the rendering (that is, the placement of the numbers and the text/line spacing), I'd think that the "Welcome" page was optimized for EdgeHTML, but it goes beyond that -- the EdgeHTML graphic is different from the one shown in either Edge Chromium or Firefox, and the action box wording is also different (Edge Chromium and EdgeHTML have a "See How" button, and Firefox has a "Learn More" button.  And just to make things even more incomprehensible, the text in each instance is also different -- Edge Chromium is "Control when you get updates", EdgeHTML is "Search the web or PC from one ..." and Firefox is "Control how you update your PC".  

So it can't just be a rendering engine issue.   It has to be that Microsoft is using different versions of the page, depending on the browser accessing the page.  Go figure.

I'm not sure that it makes any difference, but it looks to me that either Microsoft is overthinking the issue, or I am.