memes

I figured its unrealistic body standards and lifestyles? All the pictured people (mostly women) are barbie-doll skinny and tall.

I had to look up delulu, and it seems to be a reaction to that very thing:

Delulu is an internet slang term used to describe the belief that one can influence one's own destiny through sheer willpower. Derived from the English-language word delusional, the term has its origins in K-pop communities where the term delulu is used to refer to individuals who were in a parasocial relationship with celebrities and had hopes of meeting them someday. The term has subsequently been adopted by Generation Z and Generation Alpha, popularized by viral TikTok trends such as the catchphrase "delulu is the solulu", implying that self-confidence is key to achieving one's dreams, however far-fetched. Solulu and trululu are slang terms for "solution" and "truth" respectively, and they are modeled after delulu.

https://en.wikipedia.org/wiki/Delulu