In case you have your Facebook page connected with your Twitter profile, when you post a photo on Facebook, it auto tweets the activity on your Twitter stream with the link to the photo you posted.
Twitter now allows the viewer to preview the photo you posted on Facebook directly on Twitter. You do not have to click the link to view the photo.
Click on your Twitter profile and click on Tweets. Click on View photo.
You will be able to see a preview of the photo that got tweeted.