In yesterday's daf yomi in Yerushalmi (see the link to my BIL's website on the side for more info on Yerushalmi yomi) the gemara cites a braysa that if a manager tells his worker to collect food from the store and the manager will pay, then the manager is responsible to insure ma'aser has been taken from the food purchased. The gemara debates the reason why: a) because the store owner is the manager's shliach, or b) the worker is the manager's shliach to make the purchase, and then is immediatly zocheh from the manager on his own behalf all in one transaction. The difference between the opinions would play out if the store owner is someone who is pasul for shlichus, in which case only option (b) works.
The gilyon sends you to a sugya in bavli kiddushin and a machne efrayim that I happen to be learning with my shabbos chavrusa. If a women says to a man "give money to ploni and I will be mekudesht to you", the kiddushin is valid. Just as an areiv, one who guarantees repayment of a loan, assumes an obligation with no benefit received, the women can assume the obligation of marriage on the basis of someone else receiving payment. The Rishonim debate how this halacha works: is the women mekudeshet because paying the third party is the equivalent as paying her and her transferring the money to the third party, or has the mekadesh paid the third-party directly with no need for the woman to be a middleman (or woman, as the case may be ; )
It seems the Gilyon intended to draw a parallel between the cases. Option (b) above assumes that the store owner just delivers the goods, and the only relationship that exists is manager to worker. In the kiddushin case, the only relationship would be the mekadeish and the third party recipeient. However, according to option (a) the store owner is part of the equationm just like the women who has funds pass through her to a third party.
To me these cases o not quite seem parallel - maybe someone else learned the gilyon differently here. Any ideas?