Earlier quoted context omitted.
e-paper, or electronic paper, is a generic term for any kind of display that doesn't work by emitting light, which the pebble, the popSLATE, and ereaders like the nook or kindle do. What you are describing is e-Ink, which is a specific implementation of a non-light-emitting screen generally used in ereaders. That being said, it does seem that popSLATE is using a screen like what is used in an ereader, and not like wh…
The thing is, pre Pebble, everyone understood that both terms meant something that didn't use power once an image was displayed. The Pebble is the first product I was aware of that abused the term. Everyone I spoke to thought it was the same clear display used in an ereader when it's actually just similar tech to my retired Palm III.
Besides, an e-Ink screen would be a horrible experience given how the display gets used in the Pebble watch.