Subsidiary illustration of butterfly maybe not caught (5)
I believe the answer is:
inset
'subsidiary illustration' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for inset that I've seen before include "Small picture within a large one" , "Extra page or piece added to enlarge" , "Picture placed within another" , "Minor figure" , "Small map within another" .)