If you would like change the default position and formatting of the callout:
Resize and reformat the callout. Here we have resized it and modified the outline color, to red.
Click “Save as Default” under the “Full Page” dropdown
Next time you click “Full Page”, the callout will be created in that same position and formatting. (The adjustments available to the formatting aren’t exhaustive -- I included: shadows, line color and weight, and fill color.)
Clicking “Reset to Original” returns the position and formatting to its defaults.
The “Snippet” callout buttons work similarly but do not force images to letter-size proportions, like the “Full Page” callout does.