Problem: If you’re using Outlook.com or Exchange as your email and contacts solution, you’re going to find that your Outlook Contact photos may not sync or appear in iOS Contacts, iMessage or other Apple apps.
Solution: It’s because the photos you’re using are way too large in both size and resolution. In order for Contact photos to appear in iOS Contacts, it needs to be 320 wide by 240 in height and ideally around 20-30kb in size. Some people say 10kb, but my pics are working with 18-25kb.
There are lots of apps to resize/crop photos. I personally use an old version of Photoshop, but there’s also https://picresize.com/ and similar online websites now to help out.
Juicy Tools 