The 'Add a Prize Image / Slideshow' enables you to upload images into your giveaway and display them on your widget; this feature is available by upgrading to the Basic subscription.
You can upload images from Facebook, Instagram, Dropbox, your desktop, etc. You're then given the ability to crop the image to fit into the Rafflecopter entry form.
For a perfect crop, we recommend using a 350x263 image size. The dimensions of the photo slideshow at the top of the widget is 350x263. If you're not interested in using the cropping feature when uploading a photo to the giveaway, we recommend using a 350x263 image for a perfect crop. To use the cropping tool, we recommend uploading an image file (jpg, png) that's less than 250KB in size and less than 750 pixels wide and tall. The small the file size you upload, the faster it will load in your giveaway.
Prize Images Tips & Tricks
When you upload a prize image to Rafflecopter, our best recommendation would be to upload a picture / photograph of the prize that you have. After the image is uploaded, play around with it to understand how the image and our cropping tool might work best for you. There is no specific image dimension, but the with our cropping tool, the height to width ratio is 4:3 when displayed in the widget.
Note: If the image cropping doesn't allow for the entire image to be seen, we recommend adding some white-space around the image in an image editor (200px on each side of the image) and re-upload it. That will help you get the entire image into view.