Posing for a picture? (5)
I believe the answer is:
still
'for a picture?' is the definition.
(still is a kind of picture)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for still that I've seen before include "Undisturbed < , yet" , "... [STRONG LIQUOR] produced by this" , "Yet - hushed" , "Stationary" , "Even now; not moving" .)