If I, as a formally unattached female, were to send a wallet-sized photo of myself to a gentleman who had previously publicly expressed a disinterest in me, I would be acting forward and even rude. A single wallet-sized photo tends to carry the implication "and I want you to carry this photo around with you".

However, if I send the same photo to the same gentleman, but with accompanying photos on themes of "a photo of us being goofy together that he did not have before" and "a photo of us and another friend" and "Cute Nephew Moment", with a friendly note making reference to our long-established status as best friends ... perfectly acceptable, and even a touching gesture.

Whether he chooses to carry the small photo of me around with him or not -- that's his business. I don't need to know about it.