Curious included graphic whitespace issue

[Mark T. B. Carroll]

In a table I set: @Cell indent { right } indentvertical { foot } A

I want a right-indented @IncludeGraphic in an "A" table cell, like a,
1.25f @Wide @Scale @IncludeGraphic myfile.eps

It has a small chunk of whitespace to the right of it for some reason,
within the same cell.

I found I can get rid of this unwanted whitespace by changing the cell
contents to,

1.25f @Wide @Scale white @Colour @Box margin { 0f } @IncludeGraphic myfile.eps

What's going on here? Why did this workaround work?

Mark