If a favourite comes from someone I know, I'll usually figure it was sent as a hug. I remember a random new follower going back a bit in my Twitter and favouriting a tweet about failing an exam, which I found a bit weird, but hopefully it was a sympathy fave.
But for absolutely no discernible reason, a favourite seems less sympathetic than a hug so I might opt for a reply? Internet communication is unnecessarily complex, lol. Thanks to me can mean many things whereas favourites (to me) are more of an 'I like this' button. But again I couldn't tell you why and really, if someone favourites like that I think I'd assume it was a sympathetic fave or even just an acknowledgement of my tweet. Just less sympathetic than a like :lol: I'm starting to confuse myself.