How your friend's name will appear on your LINE account will depend on your or your friend's settings. There are three possibilities:
1. If you added the friend by syncing your contacts list on the smartphone version of LINE, the name registered in your device's contacts list will be displayed.
2. If you added the friend by ID search, Shake it!, or QR code (methods other than syncing your contacts list), the name your friend set on their LINE account will be displayed.
3. If you manually changed the friend's name on your friend's list, the manually changed name will appear. This will change the friend's name on your friends list only.
Your friend's profile photo will be the one that they set from their profile screen. You can change your own profile photo but you cannot change your friend's profile photo.
To see more details, please see the following article.