"Furrow brow" <v> "frown"

[panzerfaust0]

Hello. I think that these two terms, "furrow one's brow" and "frown", are very similar. What is the difference?

Context: My mother is not a fan of Trump. She furrows her brow whenever she sees him on the news.

Context 2: My mother is not a fan of Trump. She frowns whenever she sees him on the news.

It appears to me that they are very similar.

Thanks.

 

[Hermione Golightly]

I agree that a frown and a furrowed brow are very similar but people can have lines in their brow all the time without it being a sign of disapproval or annoyance. I think of furrows as horizontal but a frown can be more squeezing the eyes together to cause little vertical lines just above the nose.
Here's the notorious British chef Gordon Ramsay, looking relatively furrow-free after having fillers injected. You can find pictures of him where the lines are more crevasses than furrows.