In indeterminate cleavage the fate of the cell is not determined yet, so even if you remove it from rest of the cells it still has potential to become a whole new organism. This happens in deuterostomes (not sure if I spelled that right!)
It is indeterminate so it can reproduce into another embryo because it is not a specialized cell yet...for example the grey crescent from a frog embryo can develope entirely into a new embryo...a result of indeterminate cleavage
In determinate cleavage the cells are specialized from the beginning of the embryo and you can not take out a cell and a new embryo will develop because the cells are determined for specialization early on in development...