This is a deficient comparison as it completely ignores visual quality. While subjective quality takes effort to measure, they should've at least had objective metrics like SSIM or PSNR.
Instead, all it is is 'We ran compression X with default settings vs compression Y with default settings and Y produced smaller files'.
No, the name of the standard is always “JPEG”. The letters “JPG” are sometimes used for the file extension, but that's not actually the name of the standard.
Instead, all it is is 'We ran compression X with default settings vs compression Y with default settings and Y produced smaller files'.