The WHIH Newscast is seen at various points in the series.

Dave subtly compares Crystal to Thor by calling her a goddess of thunder.

The throne of the king of Attilan has the same Kree symbolism as Ronan's throne.

The Sokovia Accords are subtly mentioned. 

In Inhumans Episode 3, Sammy asks Black Bolt if he's been bitten by a radioactive insect.