Unsure Mr. Brown embraced by model (8)
I believe the answer is:
hesitant
'unsure' is the definition.
(thesaurus)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for hesitant that I've seen before include "Wavering" , "Expressing doubts" , "Not quick" , "Pausing - undecided" , "Reluctant (to speak, act)" .)