This screenshot was posted on twitter on several pages earlier today and it appears to be a fake. I dropped the screenshot into Photoshop and inverted the colors > zoomed in and it appears that a new screenshot was pasted in on the right area. You can see a slight difference in the black (in the negative color) colors of the pasted in area. All the posts reference a screenshot, but not the original 'like' which is not there on his account.

Even if not a fake screenshot, twitter hackers hijack and mimic pages all the time. A mundane news article could actually be a script to dump porn on an account. it is always a challenge running any high profile pages to weed these out (or any page at that but high profile pages are generally a target).