Selecting charms then switching their order, then switching back shows that charm as selected.
So in the charm tab of the cosmetics tab, let's say you have 3 charms selected. you go to switch one of them out but then switch the order of charms from rarity to name, then you switch back to rarity, which shows you have both your old charm and new charm selected which gives you a visual of the 4 charms selected. This is…