It's not a requirement per say, it's just one indicator. Your forehead is broader then your jaw width and it tapers kinda. Unless it's the camera angle that makes it seem that way.
The 2nd picture you added doesn't make it look like a heart shape. In both pictures, it looks like the camera is above you though, can you try to lower it a bit? The 2nd picture makes it look more like an oblong/rectangle shape.
I’m definitely not oblong or rectangle. My forehead and cheekbones are close in length but I have a very pointed chin when I smile 🤷🏻♀️. I added two more pics. Both with my camera phone right in front of me.
Thanks