First you have to find out what rules there are regarding stuff on the balcony. A couple of thoughts are plants in narrow rectangular planters and/or some sort of screening attached to the railing.

I am allowed to put anything including plants, chairs/table, lounge chair, Small BBQ grill but nothing that will post hazardous to people who walk underneath it.

What do you means screening..can you give me some visual ideas?

Where are u based? you could add bamboo in rectangular planters. They are great for screening (can grow to 1.5 - 2m), their leaves and form interrupt sound waves so act as an acoustic panel and they don't lose their leaves. You will need a watering system and protect them from cold/heat.

I am based in Toronto. I don't think I can create a barrier against the glass because that will distinguish me from others and base on one of the laws I am not allow to make my unit ( the common area ) sticks out like a sore thumb. I might try to look for black square plant holder (high as the knee ) and place it along the shorter part of the balcony. When the plant (possibly bamboo) grows, it will create that barrier for me.

Consider a folding standing 3 panel outdoor "screen" that you carry out DIY- perhaps with galvinized pipe pumbing "feet" connectors and pipe frame to give it more stability and echo the silver tone of the rail. You could hang fabric on it - sunbrella - so you can place it at the corner to give a wind break / make the small side more private when you are out. When not, fold it flat - so long as you move it from one side to the other now and then, it just looks like a piece of outdoor furniture or art -

You may want to consider some outdoor flooring for your condo balcony. It won't help with your privacy issue but it may absorb some noise and it will completely transform the space for you.

maybe some narrow chaise lounge to put in one corner for lounging ?
or building a custom narrow bench with pillows ?

xoxo eva @ monarchsofas.com

A hanging garden trellis would look nice.