It's funny, and it was said in jest, but for anyone looking to take the question seriously:
Alito posed IF YouTube was a newspaper, how much would it weigh in the context of showing that YouTube is not a newspaper, so principles that apply to newspapers don't apply cleanly to YouTube.
It makes perfect sense in context.
https://www.supremecourt.gov/oral_arguments/argument_transcripts/2023/22-555_omq2.pdf