How do I set the border-weight of an InlineImage in app script? The reference pages only show how to change the border width for a cell in table,
TLDR
You can't for now. There's a feature request for it here and relevant question
Full Explanation
Refer to documentation for InlineImage. By right, you can use the setAttributes(object) function to set various style attributes. However, looking at the available application attributes for images, BORDER_WIDTH applies to tables and not images.