Lolita fashion is not just like any other (alternative) fashion style. Most fashion styles have some very basic guide lines that an outfit should follow to belong to them. For example: a 'Goth' outfit should fit the dark and/or spooky aesthetic to fit in the Gothic style (no rainbows and unicorns allowed!).
Most of these guide lines are more about the overall aesthetic of an outfit, than about any specific elements incorporated in it. No set rules are given about things like 'how long your skirt should be' or 'what kind of materials (not) to use'.