This is the 8689th most frequent Russian word.
парижская
"Parisian" (related to Paris).
The adjective 'парижскую' (a form of 'парижская') is used here to describe the bun ('булочку') originating from or inspired by Paris.
Я купил парижскую булочку в местной пекарне.
I bought a Parisian bun at the local bakery.
Here, 'парижская' is used to denote that the painting ('картина') is associated with Paris, either by origin or style.
На стене висела парижская картина с изображением Эйфелевой башни.
A Parisian painting with the depiction of the Eiffel Tower was hanging on the wall.
The adjective 'парижской' modifies 'осени' (autumn), implying the specific atmosphere or essence of autumn in Paris.