There is no more red flag (at least on steemit.com; some other UIs may still use it). Actually there never was, the downvote was always a downvote, where people can express their opinion on payout value (just like upvoting and downvoting on every other site), but some genius decided to change the downvote to a flag, which made it into an attack (you did something wrong! Wave the red flag!).

Downvote simply means one thing, that the voter thought that the payout should be lower. Upvote means the voter thought that payout should be higher. That is all it means.