Is this blog a joke/prank?

The images don't link to the correct filetype stated.

- "JPEG, lossy, 85 : 184 kiB" → links actually to a WebP file (https://eng.aurelienpierre.com/wp-content/uploads/sites/8/20...)

- "JPEG, lossy, 85 : 211 KiB" → links actually to a WebP file (https://eng.aurelienpierre.com/wp-content/uploads/sites/8/20...)

etc...

So when the blog tells you that JPEG is so much better quality, the "jpeg" image that's actually being shown is a WebP image.