As a player anything that makes your DM excited typically envokes a great deal of dread . For example going out to sea giving the DM a chance to spring aquatic encounters.

But if you began to think... "The DM is too Happy S/he is thinking of something bad that is going to happen" then the DM could just fake it and make the others think something is going to happen

You can’t fake a DM that’s excited they get to pull out something they’ve prepared in advance for if the party did something stupid