You need to enter and exit the room mutiple times to see all of them, cause it resets the pond. I have done this more than a 100 times and I can safely say there is at least 15 unique texts from the pond. Here are all of them:
(Unfortunately, I was too lazy to record a video of each text, but please take my word for it that they actually exist).

"You see a boy staring at a wall."

"You see a boy staring at his fingers. He whimpers in pain."

"You see a boy staring out a window."

"You see a boy dropping something shiny into a chest."

"You see a boy crying in the corner of his room."

"You see two boys and their dog playing outside."

"You see a man shutting his car door and driving away."

"You see a man desperately hacking down a tree in the backyard."

"You see a boy burying something in the grass."

"You see a boy locking a door."

"You see a boy sitting in a dark room. The boy lies and lies, over and over again."

"You see a boy digging a pencil into his desk."

"You see a boy flipping over his bedsheets."

"You see a boy scratching his knuckles."

"You see a boy sitting at the piano. The boy plays a few notes, and mumbles something to himself."
[END OF TEXTS]

It's safe to assume that these are Sunny's memories, since they are in a pond, which is a popular representation of memories.