Each drawn molecule stands for one particle (Particles mode) or for 0.1 mol (Grams mode). Motion is sped up. The balance shows the total mass inside the closed vessel.
The picture draws each formula as many times as its coefficient (up to 8). Atoms are rearranged in a reaction, never created or destroyed.
The worked solution follows the mole map. Watch matching units get struck through, the numbers combine, and the answer appear with the right significant figures.