Image Fullscreen Pin by SilverRabbit90

Image Fullscreen Pin lets you view any image at full size and keep it pinned on screen while you browse.

When you open a direct image, the extension auto-fits it to your viewport (toggleable). From the popup you can send an image to fullscreen, pin it to a corner at an adjustable size, choose a light or dark backdrop, and set the pin position. While an image is fitted you can rotate it, adjust brightness, and reset the view using keyboard shortcuts, all of which are fully configurable — enable, disable, or rebind each one from the "Modify Shortcuts" panel.

Key features:

Auto-fit images on open (can be turned off with a single checkbox)
Fullscreen viewing and corner-pinning with adjustable size and position
Light/dark background options
Rotate, brightness, and reset controls via keyboard
Fully customizable shortcuts (single key or modifier combinations)

The extension stores your preferences locally only. It does not collect, transmit, or share any data.