Would a touching letter form buyer to seller make different

When seeing an Open house, the listing agent hinted to write seller a touching letter is the good idea. I am wondering whether this will make different at all.
Or maybe if offers are pretty comparable at the time? Or hope the letter will not make opposite effect at least.

please share if you've ever written one as buyer or received one as seller.
If you can send me a temp would be even better. Could use QQH if you prefer.