An internet wide joke to associate a specific type of person who
1. Is often into spirituality
2: Often leftist if not just left leaning
3. Has a sense of faux nonconformism despite interests/hobbies being a common trait among many people.
4. A certain (very common, mind you.) Style and overall personality. (Common interests include things like frogs, minimalistic smiley faces, and rainbows.)
Can also be used as a stereotype to describe an overall type of woman, more often than not, a bisexual woman.
Jan: Ugh, Melanie is being such an Emily right now. She thinks she's soooo special.
Mac: Yea, she bought one of those dumb frog bucket hats. It's just so unoriginal.