Draceana developed white stripes

[Sabina515]

I just put my draceana palm tree in a new pot in March. It has been neglected in the watering area, but shooting a huge leaf! I noticed there are white stripes on another leaf, not new, that formed like a varigation. Never seen this before. What is this? Plant is healthy since repotting

 

[Marck]

This is not a Dracaena. This is a Chamaedorea palm, most likely the common Parlor Palm (Chamaedorea elegans).
There are variegated forms of Chamaedorea elegans, but the variegation is not stable and will appear or disappear in random ways.