“Don't Like, Don't Look” (嫌なら見るな, Iyanara Miruna), also rendered as “If you don't like it, don't look!”,1) is a retort typically used against people who criticize or voice their dislike of a work or idea. It's a very weak retort, thus why Japanese social media has satirized it for decades.
The statement asserts that criticism wouldn't exist if people didn't see it, but the problem is that it ignores the wide variety of circumstances for seeing it and generally invites hostility, regardless of intent or not, since it does nothing to deescalate a situation. In the worst case scenario, a person who uses this retort comes off as arrogant since “don't look” actually means “don't criticize”, thus invoking said hostility.
It's generally considered bad form to criticize something without looking at it, despite it being a common sight on the internet due to the bandwagon effect. When you give baseless critique, you'll be asked to actually look at it. However, if you give your critique after looking at it, being told that you didn't have to look when you didn't like it feels bewildering, which forms the following loop:
「Don't like, don't look!」 → Criticize w/o looking ↑ ↓ Criticize after looking ← 「Don't criticize w/o looking!」
Furthermore, there are many reasons why a person might have look at a subject, despite their dislike, which range from intentional to unavoidable due to popularity, prevalence, or job obligation. Some people may be critics or have a healthy relationship with the subject matter that they can criticize it, others have a passionate hatred, then you have cautionary hatred, jealousy, and many other ugly emotions.
On the other hand, the statement does carry some validity. If a work contains divisive elements (e.g. abuse, depression, gore, homosexuality, horror, mental illness, NTR, rape, violence, etc.) and it sufficiently warns you,2) then it's odd to complain. There's also the belief that hate-watching has an inverse effect, as it can mislead companies into making more of what people hate.
This statement was so commonplace on 2channel, despite it being an anonymous website where people are generally comfortable voicing their own dislikes, that people made AA to satirize the retort. The text artwork depicts a tall character shouting “Don't Like, Don't Look” while they randomly flash their genitalia to someone, regardless of the target's will or what the target's sexuality happens to be.
ヽ人人人人人人人人人人人人人人人ノ ／￣(Ｓ）~＼ ＜ ＞ ／ ／ ∧ ∧＼ ＼＜ DON'T LIKE？ DON'T LOOK！ ＞ ＼ ＼( ﾟД,ﾟ ) / /＜ ＞ ＼⌒ ⌒ / ノ Y´｀Y´｀Y´｀Y´｀Y´｀Y´｀Y´｀Y´｀Y´｀Yヽ ）_人＿ ノ / / ∧＿∧ ■□ （ ）) （ ； ）■□ ￣￣ヽ γ⌒ ⌒ヽ ￣￣ﾉ ﾉ ￣￣￣￣￣￣￣￣￣￣￣|
∧＿∧ < DON'T LIKE？ , -（´Д｀# ）- ､ ､ < DON'T LOOK！ / ） YYYYYYYYYYYYYYYY ./ λ / / .〈 〈 〉 / / " .゛ ヽ ヽ∧∧/ /〃 ＿＿＿＿＿＿ X⌒X⌒X⌒ .／＼ つと ノ ＼ X⌒X⌒X⌒ll 二二 l 二二 lll i二二i二二i／ ／ し J ＼ ＼二i二二i ／＿＿／＿＿／ll 〈 〈（（ .～ l ）） 〉 〉 ll,＝＝ ll, ＝＝ll,"ll ＼ ＼ し^J ／ ／ ヾ ＼ ＼ ／ ／ (⌒ ） （ ⌒)
（ Don't like, don't look... ） `～～～○～～～～～～' ∧＿∧ Ｏ （ ； ﾟДﾟ）o / ヽ | /⌒ヽ ⌒ヽ ＿＿＿＿＿＿＿＿＿＿＿＿＿＿＿ | | / v | ∧＿∧ ／I took the trouble to see you today, ＼ | | / | |（ ） ＜ but your body, is seriously disgusting！| / |l. | |⊂ ）､＿＼I don't understand who'd like this！ ／ ⊂とノヽ ＿＿人 l、（＿_つつ_＿） ￣￣￣￣￣￣￣￣￣￣￣￣￣￣￣ （__＿）