Optical Illusion
Noun, する verb, and の adjective
さっかく
それがまるで自分のもののような錯覚に襲われたんです。
I was assailed by an illusion that looked just like me.
You thought you memorized what this picture looked like, but suddenly everything looks confused and different. That's because it's an illusion.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.