To ensure that all your bucket images and files display properly on your site, make sure to grant at least public-read permissions to all your bucket items. You can quickly do so by adding this bucket policy in the bucket permissions tab of your S3 console. Make sure to change the INSERT_YOUR_BUCKET_NAME placeholder by your bucket name.

{
  "Version": "2008-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "AWS": "*"
      },
      "Action": "s3:GetObject",
      "Resource": "arn:aws:s3:::INSERT_YOUR_BUCKET_NAME/*"
    }
  ]
}