Yeah I’m confused by this, isn’t it commonly understood animals dream? What other explanation is there for my dog moving her sweet little feet and barking softly while she’s asleep sometimes.
The brain structure / nervous system of cephalpods is quite different from vertebrate species I'm pretty sure. A lot of the similarities of the complexity/development are based on convergent evolution. So it's not as straightforward of a comparison. At least in this context.
Adrian Tchaikovsky's Children of Ruin gets into the cephalopod-human communication challenges rather magnificently, if you're looking for a remarkable hard scifi read, though you have to go through the (also great) Children of Time start of the series.