When you add attachments to topics or replies, these attachments will be listed under the topic/reply content. But, in many cases, it is very useful to be able to have the attached image or something else part of the content to illustrate the point without referring to attachments list area. That is why GD bbPress Toolbox Pro has [attachment] shortcode.
Insert when creating a topic/reply
When you add a new file in the topic/reply form, you will be able to use the provided controls to add that file into content even before it is uploaded. Here is the example of the file upload block, and notice the link ‘Insert into content’.
And, when you click ‘Insert into content’, you will get the attachment added into topic or reply content you are working on:
And, the end result will be this:
If you inserted audio or video file, the plugin will use WordPress media capabilities to render this audio or video as usable controls that can play the file. If you insert the image, the image will be added as an actual image. And, you still have that file listed in the attachments list. If you prefer to hide files from attachments list if they are inserted into content, you can do it from the plugin settings for attachments panel: bbPress Toolbox -> Attachments -> Advanced -> Attachments List -> Hide files inserted into content.
Insert when editing a topic/reply
If you already have files attached, but now you want to add them into content, you can open topic or reply for edit, and you will get the list of all currently attached files. And, again, for each file you will see the option to insert it into content, again, it will add [attachment] shortcode for that file.