AirBreather

JPEG also supports lossless compression.

Technically, the spec does require it, but given that we’re in a thread about ecosystem support for a file format that’s approaching its 15th birthday, it’s worth considering how many image viewers will actually be able to work without the DCT step that is the essence of what typical JPEG does.

I don’t have a Windows machine handy to test, but it’s entirely possible that maybe lossless JPEG won’t display in its default viewer.

I think you may have whooshed: this person was pointing out a “th” that slipped through.