Rosette presumably shows goodwill (6)
I believe the answer is:
favour
This clue could be a double definition.
'rosette' is the first definition.
(old-fashioned term for a token of affection)
'goodwill' is the second definition.
(I've seen this before)
'presumably shows' is the link.
I am not very happy about this link. Some or all of it may belong to one of the definitions.
Can you help me to learn more?
(Other definitions for favour that I've seen before include "Token of goodwill" , "Goodwill or special kindness" , "Give support to - kind deed" , "Blessing" , "help" .)