One of the uses of estar (not ser) is to talk about the physical condition of something, someone or a place. This specific use of estar is used for non-permanent conditions. Have a look and listen to these examples:
¡Vaya! Mis gafas están rotas.
Oops! My glasses are broken.
Sus pantalones estaban sucios.
His trousers were dirty.
¡Qué sorpresa! La habitación de mi hija está ordenada.
What a surprise! My daughter's room is tidy.
Marina, estás muy guapa hoy.
Marina, you look very pretty today.
Remember, this specific use of estar is used for non-permanent conditions. For permanent physical descriptions see Using ser (not estar) to express an essential or permanent characteristic
