Kids shouldn’t be around the birthday person and cake until after it is cut
So basically the tradition (at least in like Indian communities idk about others) is that the birthday person stands with their cake and then like all the littles come and a photo is taken and they watch as the cake is cut.
But my unpopular opinion is that while yes you want a picture of the cake before it is cut, it should either just be of the birthday person or the family of the birthday person. Because having a bunch of littles around a cake opens up lots of room for error I.e one of the littles destroying a cake or cutting it or blowing out the candle.