I sent a message to ask them, but my best guess is that it was a manual upvote from the esteemapp account here on SteemIt, so it might have nothing to do with the app. I'm waiting for an answer from the team. :-)
You are viewing a single comment's thread from:
Back in the days, chainbb did the same thing, but they randomly awarded upvotes instead of giving it to all, so it might be that comments have like 5 % chance (a random number) to get upvoted or something like that.