I know that bag and its really nice. If you are looking for an ultra casual, soft and edgy hobo, you've found one!
Old master leather is a highly distressed and washed out leather with a crackled finish (like an old master painting) that continues to shed color as you use it.
This pic is the original Tano stock pic. IRL the bag does not look like that. The color is actually a very faded, washed out aqua blue/green that is much more distressed. Its not a powdery baby blue as shown. Ill see if I can find a pic in my database to post here for you.
I dont know where you found this bag but i would ask for a pic of the actual bag before you buy it and call first to make sure the boutique has it in stock. Its over a year old.