The image displays an indoor classroom or lecture hall within an educational institution in Sofia, Bulgaria

The image displays an indoor classroom or lecture hall within an educational institution in Sofia, Bulgaria. In the immediate foreground, a light brown wooden desk holds a black clipboard with a white sheet of paper containing handwritten mathematical equations and a 3D graph drawn in blue ink. The text on the paper is in Bulgarian Cyrillic, specifically detailing calculus problems involving integrals and volume calculations. A light blue ballpoint pen rests on the desk to the right of the clipboard, with another sheet of paper showing additional handwritten content further right. A black bag or backpack is partially visible on the far left of the desk. In the midground, multiple light brown wooden desks and chairs are arranged in rows; one desk holds a folded dark blue jacket and a green plastic bottle. In the background, a large white whiteboard is mounted on a wall, covered with mathematical equations and graphs written in black marker. A person, partially visible from the chest up and wearing a light teal-colored top, stands to the right of the whiteboard, holding a marker and actively writing or presenting content on the board. The scene suggests a mathematics class or lecture in progress.