The Shelveset Comparer extension allows you to compare the content of two shelvesets without needing to unshelve any of them. You can use it compare yours as well as anyone else's shelvesets.
Once installed the extension appear as a Button on your team explorer.
Clicking on the Compare Shelvesets button will show up a panel that displays all your shelvests. You have option ofselecting two usres too and view their shelvesets.
Select two shelvests from the list and click on the compare button. You will see a tools window with files for both the shelvests displayed side by side. You can click any two files and view differences.