At 150 dpi the image depth is not a problem. Here is the 4-bit image of the 1929 Bentley as displayed on the frame for reference: https://www.instagram.com/p/CItoGRLh52n/
On the device you only notice if you get extremely close.
On the device you only notice if you get extremely close.
The image is "contrasty", showing lots of hard transitions from bright to dark. With displays of low bit-depth, the hard thing to do is smooth gradients of tonality.