It's peloric.
Peloria is a condition in orchids where the petals take on characteristics of the lip or the lip takes on characteristics of the petals. It's very common in Phalaenopsis and Cattleya alliance breeding, and even happens naturally in some species (look at a photo of
Phragmipedium lindenii, the ladyslipper with no slipper).
In the case of your Phalaenopsis, the lip is reverting back to the shape and color of a petal, but it's not quite a perfect match for a petal. That's called partial peloria. Peloria can result in barely detectable changes all the way up to complete and totally undifferentiated flower segments. Also, this form of peloria (where the lip becomes more petal-like) is much less common in popularly available orchids, but there are are other Phal clones and hybrids as well as Dendrobiums and probably other genera available with a similar "big lip" or "no lip" appearance.