Background: this bug already fixed in 1.0.5
On responsive portrait mode when you see an album you don't see the "Share This Page" block unless you switch to landscape mode.
However still on responsive portrait mode when you see a media you can see the "Share This Media" block but only those textboxes with URLs, not the social buttons.
Is this as designed? I'm still wondering: if you have plenty of space in portrait mode to show those textboxes with URLs why don't you also show the social buttons? The same when viewing an album.
Tested on Chrome in Galaxy Note 3.