Here is more of What They Really Mean What They Say (Part 2):
When they say: Nice job.
They could mean: I haven't looked at it.
But they could also mean: It's not great, but at least you got it done.
But they really should have said: Here's what I think is great, and here's what I'd like you to revise...
And they didn’t say that because: It's hard to spend time giving feedback.