I didn't find a command to copy the image of the selected image file in the help documentation.
Do you mean you want to put the selected image file into the clipboard as bitmap data?
Bitmap data? Probably, I want to directly copy the image and paste it elsewhere, such as chat software, without opening the file and copying.
You can usually drag the image/file to the chat software (or website) without involving the clipboard at all.
Dragging into the chat software will be recognized as a file, not image. . .
That's not very good chat software then, as it works with most. 
I don't think we have a built-in way to decode an image and put the bitmap into the clipboard, but there's probably a command-line tool out there which can do it and which would work well on an Opus button or hotkey. (ImageMagick might be able to, for example.)
It's something we could probably add in the future, too, either to the Clipboard command or the scripting APIs (which can already load images, and set clipboard text, but not set clipboard images). Not immediately, as we're working through a backlog of things at the moment, but I can put it on the list.
I should add, you can do it via the image viewer, e.g. select file, push return to open it in the viewer, Ctrl C to put it in the clipboard, Esc to close the viewer.
It’s three keypresses instead of one, but quite quick to do unless you need to copy and paste a lot of images at once.
Yes 