Example in the Russian Wikisource - https://ru.wikisource.org/w/index.php?title=Страница:Русский_биографический_словарь._Том_14_(1905).djvu/12&action=edit
Strange error with edit recognized text for scanned page - in the WikiEditor, scanned image in the right side look as width: 100px; height: 814px;
This is an obvious bug.
After refreshing (unstable, in some cases) and also after double switching horizontal/vertical markup this look is changed, as width: 354px; height: 532px (fits into the visible area)
This also very unuseful, becouse text is very small.
After swithing into VisualEditor, this is looks better - width: 529px; height: 794px; (for me) - but still too small.
For comparision, these pages look normal when viewed, width: 1024px; height: 1536px; (for me) - and in my opinion, this image size should be kept in the edit-mode: