I just tested it -

Holding option seems to remove the gradient shadow of the application window in the screenshot. Not needed, but it’s better in my opinion.

I didn't lose the shadow when doing this. There's a setting ...

`defaults write com.apple.screencapture disable-shadow true`

Have you ever run that? Presumably changing to false gets you the shadow again.

after copying to clipboard, you can also paste it into an empty preview window by hitting ctrl-N (with preview in the foreground). you can paste additional clippings from the clipboard as impromptu layers that you can drag around on top of the first image.

in this way, folks (e.g., product managers) can quickly compose a mockup using components from a pre-existing UI without opening up photoshop/pixelmator/affinity.

Another option is when you press Command+Shift+5 select Options. From there select to Open in Preview. From then on any screenshot will open in preview automatically.

After hitting space to go to select window mode, click select the window and its shadow, option click select the window without its shadow. Not sure why you say the option key is not needed.

You've just saved me years of my life. I can't believe I didn't know this.

Dang, these little tricks are so useful!

Combination of CTRL+OPTION works too.