OLED digital photo frames
OLED is a next-generation display technology, based on organic (carbon-based) materials. OLED displays tend to offer sharp images, great contrast and vibrant colors. OLEDs are also very power efficient, can be made very thin - and in fact can be flexible and transparent.
Back at around 2005-2010, photo frames were popular, and some companies released such products based on OLED panels to offer a better image quality compared to LCD based frames.
OLED photo frames
The first such products to hit the markets were very small. Digital Foci for examples produced 1.5-inch and 2.8-inch frames back in 2003, which were marketed as "keychain" frames. Small, but cheap - the price of the 1.5 inch was 15$. The frame adopted a PMOLED display.
There were also larger frames on the market. Kodak used to offer a 7.6" wireless OLED frame, that featured Wi-Fi to access photos, 2GB of storage - and a very high price tag ($800).