Some copypasta from DCW
Ah, I just figured out what that mirror is for! It's the reason Hotta Gaito thought Rum was female. The mirror is an accidental feminine prop like in Sato's Omiai case in the Vermouth arc, there was a male suspect who wore his watch on the inside of his wrist and misled someone into thinking he was a woman that way. If you saw someone ambiguous holding a cute little hand mirror, your brain would go to girl. I think I have Gosho's plan figured out now. We are going to have 3 Rum cases. Rum Case #1 is stars girly Rum. Next case we run into with Rum, maybe another flashback, a witness is going to come out and have a completely different idea, like he's a geezer. Then case 3, strong dude.
I can see how hand (hando) and handle (handoru) might have been confusing to rapid translators, just one letter difference if was spelled out in foreign sounds furigana. If it is the same mirror, that raises even more questions than two separate mirrors. We already know the case is weird because Kohji managed to have the time to turn on a sink, grab scissors, and then cut a mirror to leave a dying message (not to mention how he overheard some conversation about Asaka and Rum). If Kohji was in a similar situation to the victim from the latest cut glass case, then he must have known death was coming, so I guess he was cornered and knew it.
The new issues that arise is how Asaka got that mirror after someone else went to Kohji's room and had time to look over and photograph the crime scene. It could have been Asaka's mirror to begin with (so he was seen with it before the crime), but Haibara seemed to think is was Haneda's, keeping in mind that Elena nee Sera had one of those mirrors also and that the Hanedas and Seras seem to be close. I assume Asaka took the mirror in order to hide the dying message, and he was seen with it fleeing. For the photos to exist and Kohji to leave a message, Asaka must have lost control of the situation somehow. Was he distracted, or people forced their way in, or he was forced away from the scene? All I can think of is that this may be the situation that cost Rum his eye (assuming he is Asaka). Kohji inflicted the wound in desperation and bought himself some time to leave a message.