To paste a still image on your clipboard in a QT file, open the QT file and pause it on the frame where you want the image to appear. Then, take a screenshot of your computer screen (Command + Shift + 4 on Mac) and copy it to your clipboard (Command + C on Mac). Go back to the QT file and select "Edit" and then "Add to Movie". The still image from your clipboard should now appear in the QT file at the frame where you paused it.
