Issue
When the reference content contains an expandable table, the reference preview popup shows a copy of the table in it's current state (typically collapsed), with the collapse/expand button being present, but clicking the button inside the popup does not do anything. See for example the reference Übersicht 1 on https://de.wikipedia.org/wiki/Emoji.
Solution
Remove table (or other un-expandable element) and an inline OOUI notice message instead: “This reference includes a graphic which does not fit in the preview.”
Mock