So what do you mean left column? If there is no screenshot or example for others to see this can come down to the Graphics software setting not properly rendering for the browser.

I have checked Firefox on two Intel NUCs here at the museum, and both show jagged edges on the two graphics in question.

WestEnd said

So what do you mean left column? If there is no screenshot or example for others to see this can come down to the Graphics software setting not properly rendering for the browser.

I have uploaded an image showing a comparison of Firefox and Chrome, both on Windows.

Tried the link and looked where your screenshot location and it looks just like the chrome screenshot.

WestEnd said

Tried the link and looked where your screenshot location and it looks just like the chrome screenshot.

The leftmost image is Firefox; the rightmost is Chrome.

Are you talking about this circular orange logo? Or about whole image or fonts?

Yes, it's the circular logo.

I looked and yeah the ff is jagged and chrome is rounded. It could be hardware accel. Did you disable that and see what happens?

It looks like Firefox doesn't support the experimental css feature 'image-rendering: high-quality;'

On this page we have:

a img, img {
    // works in Firefox, makes image aliased:
    image-rendering: optimizeQuality; 
}

And later:

img {
    // doesn't work in Firefox:
    image-rendering: high-quality; 
}

image-rendering: auto;

image-rendering: unset;

See https://developer.mozilla.org/en-US/docs/Web/CSS/image-rendering