[Quoth]

Originally Posted by shuvashish76

It has better contrast? They say it has slightly worse contrast than previous generations of carta like Carta 1200.

See this comparison video : https://www.youtube.com/watch?v=26iD9lauEM0
Even kobo that was made 14 year ago has better contrast than carta 1300 : https://youtu.be/eYc0cJSRV_4?t=548

Video is process and compressed incredibly even compared to jpeg. You need better resolution and camera than video and an carefully lit scene and png or tiff distribution.

Edit:
Also outer layer, how touch layers is implemented, the lightpipe layer all have a huge effect on contrast and sharpness. Also any glue to bond layers.
So IR touch (no layers) used on many early models from different companies and no front light (LEDS at edge of a light pipe layer). Then sometimes quality is worse!
Voyage: One of first 6" 300 dpi Very good and expensive.
Paperwhite 3. Cost reduced Voyage, not as good as voyage, but same eink. Better than Paperwhite2 which is earlier lower resolution Carta
Oasis 1 (Really Voyage 2). Same 6" eink again, but not as good as Voyage. The Oasis 2 & 3 are 7"
Then Paperwhite 4 with flush screen. Obviously inferior side by side with PW3, but stanalone looks fine.

There is massive difference Viziplex 4 shades (1st Sony), Viziplex 16 shades (K2 & DX), Pearl (K3 & DXG) and then Carta.
Carta added a new refresh mode (regal) and reduced ghosting.
Carta HD is mostly just Carta but 300 DPI

After that the differences are more to do with the assembly, choice & quality of the layers. Carta 1300 is a tiny change to try and improve brightness.
Kaleido is tranlucent coloured dots smaller than the pixel size printed direct to the upper layer of the Carta screen. Triton was full width stripes.