1. What does it mean?
취저 is a shortened form of 취향 저격. It says that a song, design, food, person, or other subject hits the speaker's particular taste especially well.
Also written or said as 취향저격, 취향 저격, chwijeo
2. The nuance
It is a personal reaction, not a claim that everyone will like the same thing. The 저격 part is figurative here; the whole expression describes attraction or enjoyment, not an attack.
3. Examples
“이 노트의 색이랑 종이 질감이 완전 취저야.”
The color and paper texture of this notebook are exactly my taste.
“추천해 준 밴드 첫 곡부터 취저라서 앨범 다 들었어.”
The band you recommended was right up my alley from the first track, so I listened to the whole album.
Sources
Edaily: Korean fandom expressions
References support the meaning and usage. Example sentences are written for NoCapWiki.