Nandi is described as having a वानर like face in Skandha Purāna. He is certainly not a white Bull, used by Lord Shiva as his vāhana(वाहन).

The question is - who is that white bull, if not Nandi?

Traverse this thread to look at the depictions of Nandi(the one with Vānara face). https://twitter.com/GhorAngirasa/status/1090774815743459328?s=20

The white bull goes by the name of vRShabhadeva. https://twitter.com/GhorAngirasa/status/1123572716278243328?s=20

Funny thing is - Most daily soaps on Maheshwara depicted it wrong too.

Last time I watched "Devon ke Dev Mahādeva, the guy playing Nandi was hitting his opponent with fake horns.