As a point of clarification, catholics do not fall on their knees and "adore" the shroud.
The Western (=Latin) Catholic Church is prone to praying on their knees. In the above image, what an evangelical might misinterpret as "worship" is actually, Latin Rite Catholics kneeling in prayer but doing so, before the shroud. We pray on our knees, but our prayers are always directed to God ... ALWAYS!
For us, the shroud is nothing more than symbolic .. that's it. Like evangelicals, we marvel at the image. At the request of Pope Emeritus Benedict XVI, the shroud was placed on televised public exhibit this year on Good Friday. The purpose in this was to draw catholics into reflection on the image of a crucified man to better assist us in appreciating what our Lord and Savior endured on that particular day. No crucifixion, no resurrection. No resurrection, no salvation.
I concur if that is how it is officially supposed to be regarded, praising the Lord for this evidence He has created of the work of Christ, it would be a correct theological approach. I’ve struggled personally with the issue of spirits associated with “things,” and know that discernment has to be exercised because the devil can play games with what God wants to be treated as holy, but that doesn’t mean the Holy Spirit can’t manifest in conjunction with an object as well.