TOC
Media Options Test Page
Ideally you want to keep images around 0.8-1MB and crop them to have a max width and or height of around 1000px. Maybe a bit less, but feel free to play with the format and how the wiki displays them (the main yellow column is large enough, but is always around 50% of the total window’s width size), so larger than that size an image will not be displayed.
Google Doc
Google Slides
Image with Caption
Multi-page PDF
Video