OK.
The layout is similar and there's the triangle in the middle. The drawing on her belly is lacking details and instead has only symbols. So Ariana would have to know their meaning, if they represent the smaller circles. She also would have to memorize the incantation. Besides if you noticed they used various props for their rituals.
The dev can draw inspiration from various magic traditions or invent a magic system of his own.
That being said, pentagrams, hexagrams and the like are in general thought to be used for protection of the caster. Or they are depicted to be utilized to contain a summoned entity.
What they are performing could be called "ritual magic". A step above is "astral magic". Where you visualize the entire ritual in your mind. I.e. you picture the entire space where it is to be performed with all the details needed for the ritual. Then you play out the ritual in that "temple". Of course that would require strong concentration. The upside is you don't need a physical space to practice your magic. So you could cast spells while sitting on a toilet.
Yes, you can use substitutes for various items. Though it is said that the best symbol of a sharp sword is a sharp sword.
The highest form is aptly called "high magic". This state is said to be reached only a few times in a lifetime, if ever. Then you can do away with the theatrics and simply cast the spell as if you were in a computer game.