An optical security component (101, 102) intended to be observed in reflection, with the naked eye, along at least one first observation face, comprising: - a first layer of dielectric material, which is at least partially transparent in the visible range, having a first refractive index (n 1), said first layer comprising at least one first region (R 1) that is uniformly microstructured so as to form a first diffractive microstructure (S 1); - at least one first metallic reflective layer, which is deposited on said at least one first microstructured region and forms one or more opaque reflective elements (O i), each opaque reflective element forming a line with a width that is strictly smaller than 1 mm, the assembly comprising the one or more opaque reflective elements forming a first recognizable graphical element; - at least one first transparent reflective layer, made of dielectric material, having a second refractive index (n 2), which is deposited on said at least one first microstructured region and forms one or more transparent reflective elements (T i), a minimum dimension of each transparent reflective element being greater than 2 mm, the assembly comprising the one or more transparent reflective elements forming a second recognizable graphical element; - a cover layer (116, 117), made of dielectric material, which is at least partially transparent in the visible range, having a third refractive index (n 3) close to the first refractive index (n 1), covering said first layer and said at least one first metallic reflective layer and at least one first transparent reflective layer, such that said cover layer is in direct contact with said first layer in the areas of said first layer without opaque or transparent reflective elements, - the optical security component exhibiting, in reflection, a dynamic visual effect obtained by tilting the component. - a first layer of dielectric material, which is at least partially transparent in the visible range, having a first refractive index (n 1), said first layer comprising at least one first region (R 1) that is uniformly microstructured so as to form a first diffractive microstructure (S 1); - at least one first metallic reflective layer, which is deposited on said at least one first microstructured region and forms one or more opaque reflective elements (O i), each opaque reflective element forming a line with a width that is strictly smaller than 1 mm, the assembly comprising the one or more opaque reflective elements forming a first recognizable graphical element; - at least one first transparent reflective layer, made of dielectric material, having a second refractive index (n 2), which is deposited on said at least one first microstructured region and forms one or more transparent reflective elements (T i), a minimum dimension of each transparent reflective element being greater than 2 mm, the assembly comprising the one or more transparent reflective elements forming a second recognizable graphical element; - a cover layer (116, 117), made of dielectric material, which is at least partially transparent in the visible range, having a third refractive index (n 3) close to the first refractive index (n 1), covering said first layer and said at least one first metallic reflective layer and at least one first transparent reflective layer, such that said cover layer is in direct contact with said first layer in the areas of said first layer without opaque or transparent reflective elements, - the optical security component exhibiting, in reflection, a dynamic visual effect obtained by tilting the component.