I noticed that if the OP of a question makes an edit to their question or comments under their question, then in the corresponding event in the timeline the OP's username is highlighted by a grey box around to it, presumably to distinguish it from events caused by users other than the OP. (A random example.)
However, if the OP starts a bounty on their question, then their username is not highlighted. I noticed this on the timeline to a question on Music Fans SE, but I presume this is the case everywhere:
Is there any reason why bounties started by the OP do not have a highlighted entry for the OP's username in the "BY" column in the timeline? I've tagged this as support as well as bug, because I'm not sure whether this is an oversight or is as intended.