To Display a Folder of Images in "thumbnail" size:
Method 1, Step 1:
In the Finder, drag the folder with the images in it to the PhotoGrid icon or an alias of it.
Drag&Drop
Grid of Images
Method 2, Step 1:
Start PhotoGrid, and use the standard Open dialog (File menu) to navigate to the folder you want
Open


Either Method, Step 2:
   
Look at the top left of the window. Underneath some other items, you'll see a list of folders and/or files. Click on the folder you want, which should be at the top. 		Click

Note: PhotoGrid displays all the image files in a folder.
So if you select a folder with thousands of images in it, it may take a while, and you may find you don't have enough memory.

The speed at which PhotoGrid displays the images depends on things such as the speed of your Mac and the number, size and resolution of the images in the folder you've selected.

You can stop this process either by hitting any key if PhotoGrid is taking a long time even to count the images, or by hitting the PhotoGrid window's close box if the display is taking too long to finish.