High-Heel shoes that have an extremely large heel, causing the wearer to be very tall.

Etymologically related to the phrase "nosebleed section", coming from the tendency of high altitude to cause or aggravate nosebleeds.

Sources:
Since Urban Dictionary won't allow links, I'll just say my sources are the English Wiktionary for "nosebleed_seat" and Googling "nosebleed heels" to find the article titled "Are expensive or designer shoes worth the extra money?" by Alice Mancino on helium.com