The message the Shroud carries is not only Jesus suffering, but also the joy of Jesus resurrection, and the promise that He carries for all of us that accept him as our Lord and Savior.
We tend to think of people that need visual proof of the resurrection of Jesus as having less faith but in reality, they are normal. We think that Thomas was the only disciple needing visual proof. That is a false image. In Luke 24:1-12 it mentions that when Mary Magdalene found the tomb empty and encountered the angels announcing Jesus resurrection the apostles did not believe her story. They said it was nonsense. The apostles were later confronted by Jesus (verses 36-40) and he asked them why they doubted? He then showed them His hands and feet and asked them to touch Him. So, doubt is normal. God knew some of us needed to see the resurrection in order to believe and He left enough supernatural evidence embedded in the Shroud to prove it is Him. God wants His image to be shared! His resurrection is the most important message in all of human history. The very reason for creation itself is for us to choose eternal life with Him.
I look at His image all the time. It brings my spirit into reverence for Him and what He did for me. It shows how much love He has for us. To go through so much suffering but then to show His resurrection proves His promise in Scripture that we will be raised to eternity with Him simply by repenting of our sin and making Him our Lord and Savior. Praise Him for His loving kindness toward us!