We live on Earth, around the Sun and the Earth has one huge natural satellite: the Moon.
So, we live in the Earth-Moon system.

To have the best view of it, we must go as far as possible but just enough to be able to see our Earth system at once, continuously. The Lagrange 1 point at 1,500,000 km.

From there, the Earth would be full, and look as big as our Moon is from Earth.
The Moon would always be visible, though quite small, but when at its closest, it would show farside while to us it would be too close to the Sun (perhaps there'd be an eclipse on Earth).

But there are interesting figures showing how dynamic this all is:

The Earth rotates at the equator at a speed of 1,600 km/h...
The Moon orbits the Earth at a speed of 3,600 km/h....
When looking at the Earth , the starry background moves at 1 degree per day or rather, the Earth moves around the Sun at a speed of 108,000 km/h....or 30 km/second.

During 7 times 24 hours, the Earth travels about 14 times its own diameter across the background of stars and planets, The Moon makes one quarter of an orbit around the Earth...

Surely, a satellite continuously observing the Earth from L1 would not require as much energy as doing it from the Moon.

What would also be interesting (and granted, never proposed for Triana), is a stargraph hiding the Earth and showing very faint objects around the Earth (stars, planets, perhaps even satellites, incoming probes, asteroids).
Combining these pictures with those of the translating Moon and the rotating Earth, we'd finally have a good idea of where we are.
And if those images could be very sharp, detailed, as the eyes would see them, continuously, and it would never be the same, always different, different clouds, different Earth orientation, different star background, different Moon angle...And we'd finally understand where the Earth is. Geography maps would have a serious competitor in classrooms.