Several characters are the slaves of other characters, with none of this being looked at oddly or negatively. In fact, the receiving of a girl's first slave is treated more like getting a new pet than anything else, with the mother telling the girls to "take care of them" and that it's a "big responsibility". However, in actual practice the situation often seems to be "slavery" in name only. Given the general treatment of women during that time period, being a slave to an Amazon was probably a reasonably sweet deal.
Since it is set in an all-female society, lesbian relationships are the norm (usually between mistress/slave) and sex with men is considered a necessary duty for reproduction. A woman actually wanting to have sex with a man is considered a sexual deviant.
Who has sex with his female slaves (or at least heavily hinted), slaves who are under magic to be unable to disobey his orders...
More recently the issue has been brought much more to the foreground of the story, when Eric refuses to release slaves who saved his life despite of being free of the mind control spell at the time, on the basis that they were just doing what good slaves are supposed to do in any case. It turns out later the real reason he wouldn't release them is that it was illegal to do so under Templar law. He eventually agrees to "sell them" to Trace, so Trace would take any heat for releasing them.
Gunnerkrigg Court: Stated in comic by one of the characters as being one of the (if not the) major reasons why the Court and the Woods do not currently get along.
Due to the vast differences between human and troll society in Homestuck, there's bound to be some in-universe dissonance. For example, when John tells Karkat that he's not a homosexual when Karkat hints at a possible future kismesis (a type of troll romance based on mutual hate), Karkat has no idea what the word 'homosexual' means. After John explains it, Karkat is shocked that humans even have a word for it, where as it's a complete non-issue for trolls, considering how they reproduce.
Later a different dissonance is Played for Drama when Vriska tells John that he, as a human, can't understand her justifications for killing Tavros.
Most readers of Ralph Hayes, Jr.'s Goblin Hollow webcomic felt he hit this pretty badly when Penny's upbraiding an obnoxious, bigoted Jerk Ass preacher, something that was perceived as her Crowning Moment Of Awesome and a fine example of her Character Development from being a Bratty Teenage Daughter to a Grumpy BearDeadpan Snarker with Mama Bear traits, was met in-universe by Lily demanding she apologize for causing such a scene in church and promptly slapping her in the face and grounding her for a week when she refused to do so. The author was deeply shocked, even outraged, when the readers were themselves outraged by this and revolted against Lily and Ben being treated as being the ones in the right.
Penny in general being regarded as a "troubled teen", as most of the things she actually does don't come off as being anywhere near that unusual or anarchic for a teenage girl in the eyes of most readers. Her biggest signs of "being troubled" are that she's surly, not too shy about sexual matters (though still a virgin) and always wears black clothes.
An in-universe example occurs in Chaos Fighters, particularly in Lefrad, which consists of continents has different administration systems. Yedrei-Phlaq confrontation happened an unspecified time prior to the start of the entire main series, which is partly due to their leader trying to force their administration systems to others (Yedrei uses monarchy while Phlaq uses democracy. As the result, in Chaos Fighters-Route of Peaks, the government of Tziac sent only one person to join the main characters' party to eliminate the mountain bandits, fearing of bringing significant casualties to the soldiers, which happened during the confrontation. Even other countries merely used long range weaponry to eliminate them, despite sending slightly more (read: two) people to aid the main characters' party. This also leads to another dissonance where in Chaos Fighters-Route of Land, almost every country in Yedrei continent gave military support of various degree to help the Estau rebel pact, which is a military force to capture Lestreb from the demons' reign.
The mostly-defunct blog Gaijin Smash derives most of its comedy from the Values Dissonance that the writer (an American) experiences while living in Japan.
Noted by The Nostalgia Critic in "True Grit: Old vs. New", as he understands the original was made in the sixties, but he can't help but feel sorry for the snake getting its skull bashed in.
Brows Held High: Oancitizen's review of "Exterminating Angels" starts with him mentioning that the French are "famously blasé when discussing sex", then showing a clip fromLeFabuleuxDestinDAmeliePoulain where Amélie is seen counting couples orgasming at the same time. He is perplexed that the film is rated "R" in the US, but only the equivalent of an "G" rating in France itself.
That Guy with the Glasses: Most of the reviewers on the site are American and are frequently discussing super hero movies in fullest detail. To people outside the US who are less endeared about super hero movies this can often come across as being very obsessive over something that is generally children's or in the very least early teenage entertainment. (For that matter, there are plenty of Americans who share that attitude, although they are understandably more inclined to keep their opinions to themselves.) Of course, in the U.S.A. most young people grow up with these types of comics and thus feel very attached to them.
It's says a lot that the TGWTG reviewers literally ignored Steven Spielberg and Peter Jackson's The Adventures of Tintin movie, despite reviewing every other major Hollywood release. Tintin, which is an institute in Europe, is an international bestseller across the rest of the world as well, except in the U.S.A. where it remains a cult favorite. This might explain why the only TGWTG reviewer who actually discussed it was Film Brain, who is British!