The left-hand table contains all active TeamRaisers. The 'Add All' button simply replaces everything in the right-hand table with everything in the left-hand table. This means that if any TeamRaisers were active upon originally being added to the current selections, but are now inactive, they will be removed from the current selections. This in turn causes the total number of "Your Selections" to decrease; the number of active TeamRaisers is simply lower than before.