The odd thing about metaphors, especially when compared to similes, is that despite appearing more literal, they're just more direct.
e.g. "The sprinter was a raging bull".
This is subtly different to "The sprinter ran like a raging bull", which is merely a simile.
You may have heard the expression "metaphorically speaking". All this means is using a metaphor.
e.g. "Dan's headache was a killer".