The red tag is absolutely positioned in the block-start, inline-end corner of the figure (top right, in English).
This figure is position: relative, which makes it the containing block for anything absolutely positioned inside it.
The tag is out of flow: it takes up no space in this text and simply overlaps whatever sits beneath it.
Change the offsets to inset-block-end and inset-inline-start and the tag pins to the opposite corner — absolute boxes are placed, not flowed.