Basically each candidate is a column that you can pull up for more support or down for less support (or no support, as with G). The vertical scale can be seen as the most support the voter can give, to the least support the voter can give. That line that separates red from green would be the line of neutrality. Any candidate above the line is a candidate they want, and below the line a candidate they don't want. The voter could even pull the line higher up if they wanted more room to disapprove of all the candidates, or lower down if they want more room to approve the candidates.
The votes could be recorded within a 100 point range, with the line of neutrality always being zero.
Analyzing the votes is an entirely different matter. So far I haven't found a way to calculate intensity of support that actually works well. So this UI could just be a way to help a voter feel like they are being listened to, until the counting system just reverts to Condorcet. heh.