Add a photo for a contact on iCloud.com
You can add or change a photo for a contact. The photo appears in all features that share your iCloud Contacts information. You can change the photo at any time.
In Contacts on iCloud.com, select a contact.
Double-click the photo or the people icon next to the contact’s name.
Click Choose Photo, then follow the onscreen instructions. You can also drag a photo to the photo field.
To resize the photo, drag the slider below the photo.
You can also add a photo when you add a new contact.
For information about photo file types and size limits, see the Apple Support article Limits for iCloud Contacts, Calendars, Reminders, Bookmarks, and Maps.