Hi René

If I understand you´re setup correct then you have a node where you have a multiple media picker, where you pick different images. And then on another node you are choosen the item, by a content picker. If so I think something like this should work for you.

@{
  if (CurrentPage.HasValue("contentPicker")){
    var node = Umbraco.Content(CurrentPage.contentPicker);
   
      if (node.HasValue("multipleMediaPicker")){
            var imagesList = node.multipleMediaPicker.Split(new string[] { "," }, StringSplitOptions.RemoveEmptyEntries);
            var imagesCollection = Umbraco.Media(imagesList);
        
            foreach (var image in imagesCollection)
            {
                <img src="@image.Url" />
            }
    }
  }
}

Remember to change the aliases so it match your case. Try too see this documentation about using the multiple media picker https://our.umbraco.org/documentation/Using-Umbraco/Backoffice-Overview/Property-Editors/Built-in-Property-Editors-v7/Media-Picker

Hope this helps,

/Dennis