The big issue is tightness of POV. All these things say the same thing, if not in the same level of detail:
- She was extremely angry, completely losing sight of the situation and pondering violence at his expression.
- She fumed, glaring at him, and thought of slapping that silly grin off his face
- She couldn't believe what a bastard he was being. If she slapped him one, she thought, he would loose that look.
- What a bastard! A good slap across his face -- he earned it -- would wipe that look off his face
You can't, however, just hop from one to the other, because it leave the reader disoriented.
confuses because the third paragraph is an outside view. It gets worse when a very tight comment is dropped inside an otherwise loose paragraph:
because "the most darling house" reads like the opinion of the omniscient narrator, not like the characters'.
The place where I see this most often is in an opening paragraph of omniscient stage setting -- not bad in itself, as long as it's engaging -- and plop! right in the POV of the character who could not have made the judgments in the opening. It can be bad if the character could have, because then we are not sure it was reliably given to us, but it can be a serious jolt if he could not have.