Only commenting on briefly, but it's poignant (8)
I believe the answer is:
touching
'it's poignant' is the definition.
(synonyms)
'only commenting on briefly' is the wordplay.
I cannot quite understand how this works, but
'on' could be 'to' and 'to' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
'but' is the link.
Can you help me to learn more?
(Other definitions for touching that I've seen before include "feeling" , "Arousing feelings of sympathy or gratitude" , "Contiguous" , "Pathetic" , "Moving; in contact" .)