How do you setup CloudFront in P&T S3 plugin & how do you know if it works? I have the P&amp;T Amazon S3 plugin.   It's connected to my S3 bucket.  It stores a few test .PDF files.   It is working.  I am able to access the files - and the URL is that of my S3 bucket - i.e., my-bucket-name.s3.amazonaws.com/filename.pdf

I created a CloudFront distribution.   It is deployed and enabled.  

I added my CloudFront Distribution ID to the CloudFront Distribution ID field in the plugin.   Do I need to add the distribution's Domain Name to any of the plugin's settings? 

How do I know if the image is being accessed through CloudFront?  The URL has not changed - i.e., - i.e., my-bucket-name.s3.amazonaws.com/filename.pdf

I can access the .PDFs in my S3 bucket using the CloudFront domain name -- i.e., cloud-front-domain-name.cloudfront.net/filename.pdf.
I wrote up an article that might be helpful for future-people looking for step by step instructions on setting this up: Setting Up AWS S3 Buckets + CloudFront CDN for your Assets