"bellachesssei" (literally "what-a-nice-gal-you-are") used ironically to comment any female user, more often by other female users, who is posting a selfie by any purpose but looking for attention, like showing a particular dress, a piece of furniture, a place, a participation to any kind of event. It's a satirical expression used to slightly imply that anyone is an attention seeker inside. The male corresponding variant does exist ("bellochesei") but is rarely used in that way.