Pictures

• Insert > Picture inserts a picture from a file (PNG, JPEG or GIF), and asks for its alt text: the description screen readers read, and shown when the mouse rests on the picture. You can also drop a picture file on the document.
• Drag a picture's corner to resize it.
• Right-click a picture > Alt text... to change its description.
• Insert > Linked Thumbnail puts a small picture in the page that links to the full-size picture file: good for large pictures in documents meant to be read in a browser.

Alt text is kept in RTF (and through it in Word and LibreOffice). When an HTML or Markdown file is saved, its pictures are written as files to a folder beside it (document_images\image1.png ...) and the file refers to them; Save As > HTML, pictures inside (one file) keeps everything in one file instead.