What did I just obtain?

Oh my gosh, I'm doing my first ever playthrough of P5R and I'm only a few days in. I check my cardboard box in my bedroom and I just obtained SO much stuff! Is this because I played P3R on the same account? (Since I saw it gave me the SEES outfit) I also got like 100,000 Yen! Does this happen to everyone playing the game?

https://preview.redd.it/nap0o3oez5kg1.png?width=1148&format=png&auto=webp&s=bb21f9aee949ce0a91b5355478e65ae3e902086b