The significance could be that it changes the power dynamic between them. Harry has always been a bit in the dark about Snape, but now Snape has a piece of information about Harry. This could lead to Snape having more influence over Harry, or it could also lead to Snape having a newfound sense of responsibility towards Harry, especially if the fear is something that could put Harry in danger.
It could be a turning point in their relationship. Maybe Snape starts to see Harry as more than just James Potter's son. The scars represent Harry's battles and traumas, and seeing them might make Snape more empathetic.
It could be a childhood trauma. Maybe he had a near - drowning experience when he was young that left a deep mark on his psyche.
Snape might initially be surprised. He could then use this knowledge in a rather Snape - like way, perhaps to gain an advantage in his complex relationship with Harry. Maybe he'd be a bit more guarded in his interactions with Harry, or he could even try to subtly help Harry overcome his fear while still maintaining his tough exterior.
It could be a sign of an unexpected alliance. Maybe Harry realizes that Snape has some hidden motives that are actually for the good, and the basilisk parts are a valuable resource that can help Snape in his own quests, like for potions or in dealing with certain dark magic threats.
At first, Snape might be dismissive. He has a reputation for being harsh, so he could act like Harry's fear of water is a sign of weakness. However, as time goes on and he realizes the depth of the fear, he may change his attitude and, in his own unique way, try to assist Harry in facing it.
In some fanfics, Harry's fear is depicted through his thoughts. He constantly has internal monologues about Snape, like wondering what Snape is really thinking or if Snape is plotting something against him. His dreams might also be affected, having nightmares about Snape and his actions.
Well, Ivy as a bird name in Harry Snape fanfiction might have a connection to nature magic. In the Harry Potter world, there are many aspects of nature - based magic. The bird Ivy could be a creature that is attuned to a certain type of magic that Snape is either interested in or has a special bond with. It could also be that Ivy is a key to unlocking an ancient magic related to birds that Snape is researching.
The significance could be that it's a way to rewrite their relationship. In the original story, they have a lot of tension, but in fanfiction, this act of spoon - feeding can show Snape in a more nurturing role towards Harry, which is a big contrast to his usual harsh demeanor.
The significance lies in the fact that it reimagines their relationship. Snape, being a complex and somewhat misunderstood character, as a mentor can offer Harry a different perspective on things. It's like Harry gets to see the other side of Snape that was hidden in the original story.
It could be that Harry demonstrates a great deal of magical talent in a new and unique way in the fanfiction. Snape, being a Potions master and a powerful wizard himself, would be impressed by such talent. Also, if Harry shows an understanding of something that Snape values deeply, like loyalty or sacrifice, it would make Snape have a positive view of him in the fanfiction.