This should be resolved.
I saw that this particular image was being constrained by the HTML (if you click on the edit image icon, you can see that in the Advanced Settings, the end of the image URL ended with .jpg?w=150, which constrained it to 150 px across. I deleted this and clicked "Original size" and it popped back to it's original dimensions.
You shouldn't have to do this going forward, however.
Try uploading another image and see if you have better results - we deployed a fix last night for various image issues.
Cheers!