Hey everyone, both the Add picture and Attachments controls allow you to either take a picture or add one from your gallery on both Android and iOS devices (and select a file from a web browser). This was the functionality that was originally requested in this post, so I am marking the feature as completed.
I understand people would like to add multiple images at once. Currently this is not supported and is not on our immediate roadmap. We will consider this functionality but I think it is best to track this as a separate ideas post to not confuse it with the original functionality.