nostalgia filter; rose-tinted view of the past
Colloquial term for the tendency to remember past events more fondly than they were. Often used in online discussions about media, childhood memories, or personal experiences.
I end up viewing the anime from my childhood through rose-tinted glasses.
That game has a strong nostalgia filter, so you might be disappointed if you play it now.
美化 means 'glorification' or 'beautification' in general, while 思い出補正 specifically refers to the psychological bias of idealizing past memories.
ノスタルジー is the general feeling of nostalgia, whereas 思い出補正 emphasizes the distortion or correction of memories to make them seem better.
Compound of 思い出 (memory) and 補正 (correction, adjustment). The term likely originated in online communities to describe the phenomenon of memories being 'corrected' to seem better over time.