iPhone 12 front camera is only 7mp

I thought the iPhone 12 front camera was supposed to be 12mp? I just got my iPhone 12 this weekend, but the selfies look identical to my iPhone XR which has a 7mp front camera.

I just looked at the metadata for a picture, and it turns out the dimensions are 3,088 x 2,316 = 7,151,808 which is a little over 7mp. Does anyone have an explanation for this?