That turn of phrase is metaphorical in a way I hadn't necessarily thought about in particular. The dichotomy of the mind and body is a huge aspect of the human experience. Ascribing emotions to either the heart or the mind is a way of expressing that. Although our emotions are at the end of the day mental processes, they are a reaction to the sensory information we receive via th3 body, and the state of your body can color them (think of how much easier it is to get upset when you are sick or uncomfortable).

I'd say things like pride and ennui are emotions more purely of the mind, while things like love and rage are of the heart. But then there's also stuff like fear and whatever you call the emotion inspires a sense of loyalty/duty/honor that have both "mind" and "heart" aspects. I guess for me, it depends on how visceral the reaction to the stimuli is for what category I'd put the emotion in. But I think many of my emotions are based in logic, though my response may not always be logical.

Fun question. Thanks!