Hi Rene,
Thanks for the info.
What I mean by responsive is to handle it in the same way as the real mashable share buttons. You’ll notice that on a mobile phone the buttons look different. The text is removed and only the icon is shown. Likewise if you resize your desktop browser you can see how their share buttons change with the screen size as well. Just a suggestion.
Just to add to my comment about the G+ button … maybe allowing the user to choose which two buttons they want front and center and the rest hidden in the + icon?
Again, awesome plugin just thought I would throw in my suggestions to make it that much better!