Thumbnail images can also be inserted into normal page text, using a method similar to the one for "inline" links. When editing a page, click the button entitled Show pictures for inline insertion to see all the pictures registered for that page. Select a picture reference by double-clicking it, then insert the reference into the text where you want the picture to appear, again by double-clicking. References are enclosed in square brackets, and contain a unique number identifying the picture, plus an alignment option: either l or r.
Pictures will be "floated" left or right on the page, with paragraph text wrapped round them. It is best to place references at the start of a paragraph so the top of the picture will line up with the top of the paragraph. A table row can be formatted to produce a centred "strip" of images simply by inserting double commas between the references. Inline pictures are displayed at once when the page text is saved, but you will need to use the "View page" option to see the full effect. This link gives more detailed advice about layout, with code examples.
By default, clicking on an image causes it to be shown on a separate page in the standard way, but there is an alternative option, selectable via Customisation/Choose option in the Admin menu. If the option labelled Inline pictures: special effects is ticked, clicking any inline image on the site will cause the corresponding full-size version to be shown as an overlay on the current page. From there, visitors will be able to move backwards and forwards through all inline images for the same page, using the mouse or cursor keys.
If an image is shown inline, editors will normally set the inline only option to prevent it's being also shown in the sidebar. But it will be possible for an inline image to be shown on another page as well. To make it available for a different page, use the Change picture option as usual, select the new page title from the pull-down list at the top of the data entry form, then click the button which says Copy to another page. That will produce a second database entry for the picture, associating it with the alternative page.