It is possible to do it by hand on the Mac, but it is a bit messy and involves the use of Photoshop and ResEdit. Like this: Render your picture. Export the image from Poser. I export as psd. Add the item to your library, and you'll get the prerender thumbnail there. Open your exported picture in Photoshop, resize it to 91 x 91, do Select all & copy, so you have the image in the clipboard. Then go to Finder, find and open the folder where you saved your Poser item. Take the cr2 or whatever and drop it on ResEdit (I have an alias on the desktop). A little window will open with one icon. In Resedit go to menu item Edit:Clear, and then Edit:Paste. Finally File:Save. Back to Poser, and when you refresh you'll see your new picture.