1. Require (ing) a lot of work/attention to maintain.

2. Require (ing) a lot of money or attention to appearance.

3. Require (ing) a high emotional investment or en excessive amount of money.

EXAMPLES OF HIGH-MAINTENANCE BEHAVIOR:
-Having frequent professional cosmetic consultations, such as hair-dressing, manicures and pedicures
-Excessive worthless spending (tricking)
-Attention craving
-Being too delicate or suavé

Referring to the heavy unfashionable winter jacket and patterned mittens Sanders wore to the inauguration of Joe Biden.

Requiring a lot of attention. When describing a person, high-maintenance usually means that the individual is emotionally needy or prone to over-dramatizing a situation to gain attention

A person who has expensive taste (re. clothing, restaurants, etc.).
This person is never comfortable because he/she is constantly concerned about his/her appearance.
This person feels they are better than most people and usually judge others based on outward appearances.

1. Requiring much time and many products to keep their appearance at the current level. 2. And/or requiring much attention from others in relationships, romantic or otherwise.

having expensive taste and multiple costly needs frequently.

A gluttonous queen, narcissistic and mean.