I left a comment at the flow-enabled talk page Talk:Beta Features/Hovercards. Another user replied to my comment, beginning the reply with "Sven Manguard,". He also (I presume) clicked the thank button under my comment.
I received a notification telling me that the other used thanked me for my comment, but I did not receive a notification telling me that I had been mentioned in his reply. On non-flow pages, if someone linked my user name like that, I would have got a message saying "Jaredzimmerman (WMF) mentioned you on the Beta Features/Hovercards talk page in "What happens if I click an image?"".
I hope that this is fixed when Flow deploys to the projects. Being notified that someone mentioned you is important, as it is the best way to keep track of when an intermittent conversation has become active again, and is a good way to get another user's attention in a quick and casual manner.
Let me know if you need any additional information.
-- Sven