When im on the Best in bags page it says on the left side
" The order matters
Setups are optimized in order from top to bottom. Drag and drop to re-order."
But how? i cant drag any of my gear slots around
Please teach me 
Point to the ‘pile of dots’ on the left end of the character name & drag the whole thing up/down to where you want it to be.
To elaborate a little further: in this example I have said that my Fury M+ build is most important to me, protection is second most important, and arms is 3rd. The main impact this will have is on gems and enchants. You might have a ring that is the best item for both the fury and protection sets of gear, but it will prioritize gems and enchant for the fury spec, and the protection spec will work around that to make the best setup possible without messing with your fury gems/enchants.
If at some point you switch to playing Protection as your main/most important set of gear, drag it to the top and re-optimize.
ok thank you so much, i completely misunderstood this drag and drop. i was thinkin i could drag my trinkets above my shoulders if i wanted to prio trinkets in the sim. but its about the setups
Thank you again for fast answers