Why do guys like your picture months later?

This is a guy who would randomly watch my stories for a few months then I eventually followed him and he then followed me back. As of recent he has started to like my pictures (that I posted years ago) what does this mean. We did grow up together but have lost contact for years, he’s a few years younger than me but has grown to be really attractive. What should my next steps be?
Why do guys like your picture months later?
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