This paragraph does not establish a containing block for any of its descendant elements that are absolutely positioned. Therefore, the absolutely positioned boldface element it contains will be positioned with respect to the initial containing block.
position: relative, this paragraph establishes a containing
block for any of its descendant elements that are absolutely positioned.
Since there is such an element-- that is to say, a boldfaced element
that is absolutely positioned, placed with respect to its containing
block (the paragraph), it will appear within the element box generated
by the paragraph.