Pandora Thumbs: Bug or Feature?

When a song is playing in Pandora, the user has the ability to give the song a “thumbs up” or a “thumbs down”. I noticed a different user experience when comparing Safari vs. Chrome (both on the Mac Lion OS). 

For Chrome, when the user moves the mouse over the visual for the song, three things are shown: (1) the “thumbs up” button, (2) the “thumbs down” button, and (3) the triangle that leads to more options. 


For Safari, only the “thumbs up” button is shown. The “thumbs down” and the triangle for more options are missing. Once you move the mouse to the exact location of where the “thumbs down” and the triangle are expected to be, then they are shown. 


I’m fairly certain this is a bug – and not an experiment for a new feature. It is a bit confusing to move from a treatment where all three buttons are shown to one where only one is shown. The only justification I can think of for having the Safari treatment is to encourage users to give the “thumbs up” and not give the “thumbs down”. But even that is a stretch considering Pandora wants to learn from your preferences and feed you songs that satisfy your individual taste.