Popa, you could have addressed your question to me, since I’m the one who brought it up.
The answer, of course us no, but a lot of tznius is not about things that are inherently untznius, but about proper and wise gedarim. Generational difference is definitely an important factor in determining what level of relationship/friendliness is appropriate.
My issue with WIY’s comment was in assuming that Torah613’s neighbor’s sending cookies was in any way related to some kind of breach of proper gedarim. Age is but one of many ways that giving cookies would not be a breach.