The Lego Batman Movie has this line by Batman:
Hey Mom, hey Dad, I saved the city again today. I think you would have been really proud.
Here, Batman is speaking to his mom and dad in his family picture. They are long dead at the time of speaking.
If they were alive, the conversation would have gone like this:
Batman: Hey Mom, hey Dad, I saved the city again today.
Parents: We are really proud.
Based on this hypothetical response of his parents, I'd think that Batman should have said, "I think you would be really proud". But he said "I think you would have been really proud" instead.
Why is that?