In the latest beta (1.8.0.10) you can now feed pandas by hand. I was just testing out some of the new things and noticed that when pandas eat bamboo the particle texture is different from what was shown off at MINECON Earth 2018. In the beta the particle textures is the same as when you break wood while in the video shown at MINECON Earth 2018 that showed pandas for the first time had a texture more similar to that of bamboo.