Absolutely correct @chantal! 
The weights you set when you create your pie are your target weights, which is how your AutoInvested funds will allocate to your slices on each deposit. Depending on market movements some of your slices (target weights) can go over or underweight, which is where rebalancing comes in hand. This is when you can use the option to sell overweight slices and buy more shares for your underweight slices.