Set your Google profile photo and cover photo

Google has changed the dimensions on the Google+ profile covers. You may want to check yours and see what needs to be done to correct it.

Set your profile photo

Setting your Google profile photo helps your friends and family find and identify you in Google+. Your profile photo shows up whenever you interact with someone, so pick a photo that really represents you.

Upload and edit your profile photo

Follow these steps to set or change your profile photo:

1. Sign in to Google+. Place your cursor in the top left corner for the Google+ main menu and then click Profile.
2. Hover your cursor over your current profile picture, then click  in the center.
3. Upload a new photo, choose one from your albums, or take a new picture.
4. Crop and edit your photo. Learn to edit Photos.
5. Click Set as profile photo when you're done.

Any new profile photo you upload from your computer will also be saved in your public "Profile photos" album and can be accessed from "Albums."

Set your cover photo

Your cover photo is the large photo featured at the top of your profile. You can use it to showcase your personality by displaying a recent travel photo, your best friends, or something else special to you.

To set or change your cover photo:

1. Sign in to Google+. Place your cursor in the top left corner for the Google+ main menu and then click Profile.
2. Hover your cursor over your cover photo and click Change cover.
3. Upload a new photo, choose one from your albums, or select from options in the gallery.
   • Recommended size: 1080 x 608
   • Minimum size: 480 x 270
4. Crop your photo.
5. Click Select cover photo when you're done.

source: https://support.google.com/plus/answer/1057172?hl=en