2 brothers,
on the left Paphiopedilum White Knight "Guinevere" AM/AOS, a green white form of the cross
On the right, Paphiopedilum White Knight "Full Moon" a pure white form of this cross
And if thaianum is a true brachipetalum, small différent leaves, pouch with spots like emersonii ans scented...may be a parvisapalum...not a niveum form...