Why were menstrual underwear ads deemed inappropriate?

Talking about women's bodily functions is still controversial. Period.
Talking about women's bodily functions is still controversial. Period.

Adventures in menstruation: how period product ads have changed to

Libra ad depicting menstrual blood did not breach standards, watchdog rules, Menstruation

Culture and menstruation - Wikipedia

Why were menstrual underwear ads deemed inappropriate?

Period underwear is better for the environment, but does it work

Safest Period Underwear Tested for Indications of PFAS -- Guide

The evolution of period product advertising - Thrive

Why Do Period Product Commercials Use Blue Liquid? The Practice

Newsflash: Women Want Accurate Period Ads

The Science Behind Period Underwear - Racked