I noticed that on Apple's website it shows the name of a contact as well as their picture towards the top of the screen while on a call. (Like in the picture posted - straight from Apple's website)
However, when I call someone and have a picture of them in my contacts it just shows their picture as a giant contact wallpaper during the call.
I know it doesn't matter too much, however, I am just wondering if there is a way to change this or what. I am on a VZW iPhone also, I don't know if that matters or not.
Short answer is that generally speaking if you add the contact pic via the phone, it will be large. If you add it to the contact on your computer and then sync the contact, it will be small.
There are some exceptions...I believe if you use Google to sync your contacts, you will always have small contact pics. At least that's been my experience.