Don't see the advantage of eInk for a digital photo frame. Presumably these stay in one spot and can be left plugged in? Would think that a bright LED display would give much better picture quality.
I'm even pretty annoyed at spurious LEDs. I appreciate for example that Sonos speakers let you turn off their status LEDs. It just makes the ambiance calmer.
The exception is very interactive stuff like https://hackaday.io/project/190477-hyelicht where I used an LCD for the embedded touchscreen in the shelf, but powered down unless you touch it.
You'd be right about the superior picture quality, though, but as the common use would be family photos that you see in passing to make you smile and may be quick snaps, the quality of e-ink is likely to be enough when it's a quick photo of your loved ones.
Some people do not like the idea of powering a device they are not actively using. If you are not watching the piece, a «bright LED display» seems like a waste of energy.