I'll teach you something that saves space in your upload quota for WhatBird but still displays the full file. You need to have the photo uploaded to eBird first. Open the separate Macaulay Library link. Click and hold on the picture as you drag it up to the top so that it opens in a separate tab. Then copy the link of the new photo into WhatBird's "Insert image from URL" box.
So the link for your red-breasted nuthatch picture looks like this. https://cdn.download.ams.birds.cornell.edu/api/v