I only have one point too make and that is for their long term survival, they are getting too much sun. If you look at your images that you provided, the proper amount of light should not produce those sharp shadows. No where near it. The light that they need should at the worse make a weak, fuzzy shadow.
Your Phalaenopsis are shown sitting in light strong enough to grow Cattleyas or maybe even Vandas!
That piece of fabric is not cutting the light nearly enough.
