How do you define "harm"? I think there are reasonable definitions by which it would be considered "harm".

Many jurisdictions worldwide criminalise exposing people to pornography without their consent – see for example, Sexual Offences (Scotland) Act 2009 section 6 [0] – and especially doing it to minors. Criminalising doing something to someone without their consent constitutes an official judgement that such an act is harmful.

[0] https://www.legislation.gov.uk/asp/2009/9/section/6