Let's clarify. Not all meals should ever be the same. When you have an unhealthy relationship with food, you think this way.
You should always include a variety of meals, snacks and colours during your day. It's all about nourishing your body with all the food groups!
An easy way to understand how to plate is by understanding balance. Not everyone has the same balance, likes, dislikes, preferences and this is why it's so confusing. I can eat completely different and should eat different to you, your mum, brother, children!
Eating the same thing over and over again may get boring and may cause you to hate food. It can lead to overeating and weight gain because of your thought process thinking that the way you are eating is "healthy."