Do I need to mail Form 8453 to the IRS?

I finished my return and filed it electronically via Turbo Tax. I was then instructed to print the following document: 1 page, Form 8453, on which the last box was check, Form 8949. It's my understanding that Turbo Tax will have already filed Form 8949 electronically with the rest of my return, so I am supposed to mail this one single page, Form 8453, with nothing else, to the IRS?

This is very confusing because Form 8453 indicates that the Check box identifies the attachments. Which leads me to believe that I need to mail Form 8453, along with Form 8949 as an attachment. 

Please clarify what the correct process is and why this one and only page (Form 8453) was required to be printed after I filed electronically.