It is nice to see that they matched the horizontal resolution of the displays. They missed that detail on one of the 16" models, with 2560 connected to 3840. That would be less big of a deal if Windows released a patch to make extended display setups and their configurations properly account for DPI scaling settings from an alignment perspective, but having them match is probably better either way. In any case, it's a shame the particular matte finish they used makes the bottom display look so grainy. I can only imagine they did that because the display points straight up towards the sun or ceiling lights.
Secondly, this OLED+LCD setup might also bring one of Windows' small but noticeable visual bugs to light: when the taskbar is set to auto-hide, using the mouse cursor to reveal it can cause it to temporarily show up on the top of the screen below, which is a bit cheap feeling from a UI perspective. With the OLED, users might set the taskbar to auto-hide to improve longevity -- if it isn't already set that way out of the box. (Or one could just set the bottom display as primary so that it shows up there instead).