Good lookback pose, and I like detail and colours on the finch. I would maybe CW rotate the thistle so the stem is vertical. I dont believe it would affect the pose of the finch.
I like this picture much more than your other goldfinch picture. Great light and details ... the bright diagonal line is a little disturbing. If is a setup I would move the thistle to a spot where this -I guess a tree- not in thebackground.
I forgot ... as a trick you can use a toy or some other new unknown object and place it near the thistle .... often the bold bird (your juvenile) will be more neophobic and will wait longer to return to the thistle than the less bold fully molted males. It doesn't work always but helped me quite often to get at leat a couple of shots from birds which otherwise would have no chance to get the handouts.....
Cheers from currently Moreton/Wirral
Geraldo ... saw lots of beautiful adult males in Leasowe including two striking Linnets.
Handsome perch and great composition. I agree with the comment about the light stripe, and certainly worth trying to get the fully-colored male. Interesting suggestion from Geraldo.