He discusses this piano at length starting at 4m30s.

From Yamaha Directly Played by Elton John on tour, this one-of-a-kind instrument is the result of our quest to find the bare minimum required to express the qualities of a piano and features Yamaha's CFX full concert grand piano action hidden within an acrylic panel.

We employed computer graphics to gauge how stage lighting from different directions would reflect off the piano and to predict the kind of outlines it would create. This effort shows in the way the clear acrylic scatters light with a prism-like effect from the triangular legs.

The images on the LED monitors embedded around the edge of the acrylic case synchronize with the show lighting, helping to harmonize the piano with its surroundings on stage. Supported by the clear acrylic of its legs, the piano body is transformed instantaneously by these images from a bare slate into a wondrous spectacle that matches each song being performed.

The relationship between the movement of the fingers with the action and hammers can be clearly perceived through the smoked acrylic front board, asserting this piano's identity as an acoustic instrument. The design also emphasizes the delicate associations between the different components that define so much about the piano while taking into account the thermal expansion of the acrylic caused by heat from the LED monitors.

Elton John requested that this piano be a truly inimitable, almost like a high-end sports car. In response, we utilized genuine leather around the keyboard, just like that found in such an extravagant automobile. Our design stresses the importance of touch, with special emphasis on the cushioning and stitching.

In this video, she talks about the Yamaha CFX and how it contributes to her unique sound and style.

Throughout this video Annie Lennox is seen with a Yamaha Concert Grand Piano CFX.