Hi, I've been experiencing this problem for some time now but never actually identified the cause before today.
When I select certain brushes, a digital image of the brush sometimes pops up. Clicking on it switches between very different modes (A and B), and has contributed to a lot of confusion in the past.
Anyway, I finally figured out today the cause of these strange occurrences (I had probably been accidentally clicking in the squares A/B unknowingly in the past) but have no idea what it is called. I merely wish to find out more about this perplexing Photoshop feature, since looking up keywords like 'photoshop brush angle' have done little to help me.
Please post if you know what this strange function is called or have links to more information. Thanks in advance.
I’m actually on CS6 but I think clicking will simply give views from diferrent axis.
From the Reference:
Bristle Brush preview
Shows brush tip that reflects changes to settings above, as well as current pressure and stroke angle. Click the preview window to see the brush from different sides.