Social media narcissist refers to people who're curating social media images of themselves. 

“社交媒体自恋狂”是指迷恋上存在于社交媒体中虚幻自己的人。

One of the most common refrains about the explosive growth of social media is that it makes many of us "narcissistic." Too many people stare too intently at their highly curated images and plunge through our screens into a bottomless sea of inauthenticity.

对于社交媒体爆炸性增长原因，最普遍的一种说法就是因为它满足了许多人“自恋”的情结。太多人整天过于痴迷地盯着高清图片或是对着屏幕，沉溺在无尽的虚拟世界中无法自拔。