Ostentatiously aesthetic party piece (4)

I believe the answer is:

I'm a little stuck... Click here to teach me more about this clue!

'ostentatiously aesthetic' is the definition.
'arty' can be an answer for 'aesthetic' (I've seen this in another clue). I'm not sure about the 'ostentatiously' bit.

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for arty that I've seen before include "Pretentiously affected" , "Affectedly interested in creative pursuits" , "Affectedly pretentious" , "Affectedly highbrow" , "Keen on cultural matters" .)

I've seen this clue in the Evening Standard.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.