That would be "facing", "ponting towards" or something like that.
"De frente" and "de costas" refer to the front and back of the subject:
- Eu estou em frente à escada = I'm in front of the stairs
- Eu estou de frente para a escada = I'm facing the stairs (The stairs are in front of me)
- Ele está de costas para mim = He has his back to me
I am Brazilian and I'd say that actually in this situation we would use "fica" rather than either "está" or "é", it would sound more natural. But if you are doing an language task and need to use "ser" or "estar" go with "ser (é, in this case)" when it is the location of a place and "estar" when it is the location of an object