Two columns in parallel, in the left column years, in the right column BMW cars that were (probably) introduced in the corresponding year. From top to bottom, the grilles of the BMW cars in the front get increasingly absurdely large, until in year 2050 the whole car turns into a (literal) radiator on wheels. 2017: BMW car with a relativily small front grilles (only on top of the sign). 2020: BMW car grille covers one third of the front. 2025: grille covers the whole front. 2030: grille covers the whole front and the engine hood. 2050: the whole car is just a radiator on wheels.
https://toot.bike/system/media_attachments/files/112/536/986/909/870/917/original/c1e47a8768333e82.jpg