The images show a particle getting close to the cell and being engulfed by it in a vesicle. Therefore, it is a type of endocytosis. As it does not surrounds the particle, prolonging its membrane to the outside, it is not phagocytosis. As it does not need the mediation of receptors, it is not a receptor-mediated endocytosis. The particle is engulfed along with a small volume of fluid during an invagination of the membrane, therefore it is a pinocytosis that is occuring.