Pix can be told to open images in 3 ways. The first way is by the usual Open… Dialog in the File menu. The second way is to drop an image file on Pix's icon in the Finder. The third way is mentioned in the "Thumbnails" page.
Pix then scales the image to the maximal possible size fitting on the main screen and displays it. EXIF data indicating a rotation of the image, which some digital cameras adjoin to an image, is recognized. The image can be rotated by π/2 or -π/2 using the respective menu commands. By dragging with the mouse a region of the image can be selected. Hitting the return or enter key opens the selected subimage in the same way as the full image was opened, in a new window. Clicking in the window removes the selection.
The file name, the zoom factor and the compression are displayed in the title of the image window, in the format
<file name> @ <scale> | <compression>
If the file contains data not really belonging to the image, like e.g. an HTML document, this title is preceded with 💩.
One can also get this information, plus the real resolution (width and height in pixels) and the size of the garbage data mentioned above, in an extra window via the Information menu command. If this window is left open, it always displays the information for the window that was most recently brought to the foreground.
Media can carry a mark, which is indicated by a ❌ at the start of the window title and corresponds to a file label in the Finder. The mark is toggled by hitting the M key on the keyboard while the medium is displayed. Now what's this good for?: You can configure Pix to skip marked media in the slide show.
The settings of Pix determine where on the screen the picture window is placed: at the left, the center, or the right side of the screen. In the settings you can also command Pix to display the image's size (in pixels) in a small rectangle in the upper left corner of the view.
The menu command Delete moves the respective file to the trash (if it is on a local volume; if it is on a remote volume, however, the file is copied to the local trash and deleted in the remote location) and closes the window.
The menu commands Copy URL, Copy Name, resp. Copy Path copy the URL, name, resp. the absolute path of the displayed image file to the system clipboard.