The phrase comes from French street slang, where asking someone if they are in Lacoste TN mode is a joking way of commenting on a very recognisable sporty outfit. Shared as a short voice clip, it spread through French meme and fashion videos, where creators paired it with tracksuit fits, trainer close-ups and playful outfit checks. Its appeal is its specificity: anyone familiar with that style hears the reference instantly. That shared recognition keeps it useful for quick, funny edits rather than longer explanations.