Why cut-n-paste image into Apple Mail will get auto converted to TIFF sometimes?

[IssuesGuy]

I have this hair-pulling frustration dealing with images cut-n-pasted into Apple Mail from websites. You would expect cutting a jpg/png image from the web into a blank Apple Mail would stay as original jpg/png format, but no, Apple Mail will convert it to TIFF behind your back and render the image size pull-down menu (large medium, small, original size) useless. The only way out is to always save a web image to desktop first and then drag-n-drop into Apple Mail. What gives? Anybody know?

Chrome: 73.0.3683.103
Apple Mail: 12.4
MacOS: 10.14.4

 

[a2jack]

No help here. I have to drag to the desktop too. But strange about 1/2 the time I can go direct. a2

 

[IssuesGuy]

Yes, that's the thing! My experience has been the same that about half of the time, direct drop does work. So what is that intricacy that makes a particular image drag into a TIFF?! Very peculiar. TIFF reader is not even built into the Windows OS, so everytime I unknowingly send a PC person an email with inline image, he/she couldn't read it.

 

[dwig]

...You would expect cutting a jpg/png image from the web into a blank Apple Mail would stay as original jpg/png format, but no, ...

No, you wouldn't expect it if you understood how the clipboard, the "channel" through which copy and paste functions, actually works.

The application where the copy is performed "publishes" either the actual copied data or a token in the clipboard. Often several formats are published. Then, the pasting app chooses one of the available formats when pasting.

Any pasting app is limited to the formats copied, and unless it offers a Paste Special (name varies with app and OS) where the user chooses which format, the app will have a hard coded selection list as to which format to prefer. A very few app offer a custom copy version of Paste Special where you can choose a single format to copy so that the pasting app has no choice.

Either way, a JPG image viewed in a browser, or any other app, is no longer a JPG when displayed. It has to be converted to the system's display format. The copy function will usually work on the displayed image (no longer a JPG) rather than the source image.