This creature looks like a Bushbuck in shape, but the colouring is wrong. I chose Impala - but is it? The eyes are so big
I think you were right to classify it as an Impala. A Bushbuck has quite straight horns compared with an Impala, and also has a distinctive grey-brown collar. The eyes are made to look bigger than they really are by the camera flash - it can sometimes exaggerate the shadows around the eyes.