Hi,
It is vital for practitioners recognise and value individuality. Think about if you had a child that had different likes or beliefs to you, would you not let them talk about them, or not celebrate it? Even if it is a baby and the parents have decided to bring them up a certain way, as long as it's appropriate, you must ensure you make no judgements. Things like: 'I wouldn't feed my baby that', or 'I wouldn't let my child wear that' is inappropriate. Think here on what affect it would have on the child? Perhaps they realise you think they are 'different' does that mean they are in the wrong and should change? Maybe they over hear you say something against their differences? This will harm the child in the fact it will lower their self esteem and confidence, but also lower the chances of them participating in their own learning and development. For example, them believing they are 'no good' or 'wrong'.
Also think about a disabled child, because they have different needs to another child, it is essential the practitioner meets and promotes them. Firstly we would not be fulfilling our role if we didn't (which also abides by the Equality Act) and secondly this child could be missing out on vital life experiences or developmental chances because we are not valuing their differences and promoting an inclusive practice.
Hope this helps