One who does a formal act of acquisition to acquire something for someone else - the Gemara now says that won't work, in contrast to the previous Gemara. The comparison to a debtor and creditor explains why. Plus, a rider asking for the reins of the animal he's riding - where the language used makes the difference. Also, a new mishnah: one finds an item and another party seizes it - who has acquired it? Plus, proximity isn't enough to acquire an object. The illustration case is pe'ah, acquiring the produce from the corners of a field - where the acquisition might be accomplished by proximity, but it's private property, so that won't work. Plus, how the 4 amot (proximity) acquisition takes effect.