That's obviously not a recreation of the supplied mockup image, but it provides a great head start. I asked my in-house Copilot how long it would take a user to code all that up by hand and it ...

Open an HTML document that has an image and find the document's section. Paste the code shown below inside that section. This code creates a CSS class named stretchX.

Now if this was the HTML page itself, it would be pretty easy to send an HTTP header to clue in the browser (force expiry IIRC), but the browser will ask for the image in a separate connection ...

The following code adds the image HTML code to the post: Replace the PNG file name with your thumbnail image. The image can be one on your website or an external image website.