Thanks for contacting Syncfusion support.
We have provided response in both DocIO and DocumentEditor to insert the picture in document.
We suspect that your requirement is, to add and manipulate the pictures, OLEObject and ActiveXControls in the Word document. Please refer the below details to work with elements (like InlineShape) in DocIO.
Currently, we don’t have support for inserting shapes in DocumentEditor. We are on track of implementing Shapes support in DocumentEditor which is expected to be available on our 2019 Volume 2 release.
Now, you can track the status of this feature from following feedback link.