OK.
If it's a small, very thin-walled, isoceles triangle then the system thinks it's better than what you have.
If it's a stylized arrow pointing to the right it's what you have equipped.
If it's a tiny, solid, equilateral triangle then it's a "Favorite". (I think that's what the Favorite icon is - I'm not in my game right now.

)
Edit: A "Favorite" is denoted by a small solid pentagon (non-equal sides) pointing to the right.