Responses
I have a little similar understanding, Hyo-Un preserve a part of his subconscious inside the Orb along with his memories before giving it to MC cause he knows MC will lost some of his memories when he absorbed the Orb or his memories are inside of the Orb cause it's Hyo-un other half
When MC finally acknowledge the Orb, Hyo-Un subconscious gave him a little tour, But MC being all inlove to Hyo-Un made an interaction with a memory and thus it gain consciousness at the end of the chapter cause he recognized the alive MC was interacting with him.
my interpretation is the orb hyo created froze specific timelines of their past together and his own life after his passing. the orb is only confused because all it knows is that tae’s dead!! the memory understands he’s real but not how he exists: they had no understanding of why tae is even reincarnated or alive (something we still don’t have answers to)
to simplify it even more: the memory of hyo is aware it’s a memory, so seeing tae alive and well in the flesh is heartbreaking and shocking it because he’d do anything to see him alive even if it’s just a figment itself