I really know nothing about Xyllobium except that I had one a few years back and the bloom was nothing at all like this! As I recall, they were more like a dendrochilum. Sorry, I know that's no help!
I have only Xylobium colleyi, and I'm sure it isn't like yours; I guess Xylobium variegatum, see the pic attached (from |::| Orquidário 4 Estações |::| +55 11 4555.2466 , a good vendor in Brazil). Except for the 'fold' in the extremity of the lip, they are very similar!