Based on the context provided and common historical knowledge, the most likely impact of the engraving on American colonists would be:
By confirming the repressive actions of the British government, the engraving would increase the desire to rebel against it.
Engravings and illustrations played a significant role in shaping public opinion during the American Revolution. Such images often highlighted the perceived injustices and oppressive measures taken by the British authorities, fueling the desire for rebellion among the colonists.