Feature Request: New capture button on the post-capture dialogue.
If you see Window 11's default screen capture utility from Microsoft, it allows you to draw an area on a static screen (the screen freezes), and to move/resize that selected area. In Gnome Screenshot, on the other hand, it is a lot more likely that you would make a not optimal selection, and want to take a new screenshot.
Doing it again is currently cumbersome because you must click the "Cancel" button, wait for the UI transition, and then click "Take Screenshot". If the post-capture dialogue had "Take screenshot" button, it will be just one click.
If you think that there is not enough space in the toolbar of the post-capture dialogue, I think space can be saved by replacing "Copy to Clipboard" with the common clipboard icon. That icon is so universal, that almost all users would recognise it, and it can also show tooltip "Copy to Clipboard" when the mouse cursor is over it. Of course, I think "Cancel" can be also replaced with a back arrow button like that of any browser or file manager. This icon should also be very intuitive.