Base Resolution Question is confusing

When I create my own template uploading an image I scanned in, I am presented with a question to pick the base resolution. 3MP, 2MP, 1MP. I am assuming that it needs to understand how to scale the zone coordinates to proper coordinates so that it can figure out 'relative' pixels instead of absolute. But I am wondering why I am being asked this question anyway??? Can't the TB app see what the resolution is of the image I uploaded programmatically? I would think it needs to make uploaded image -> selected areas (does desktop screen resolution effect this?) -> device camera resolution. Shouldn't the app figure all of this out and not have the user select the wrong values?

 

I have no idea what MP my scanned in label was. And usually the scanner will present options in DPI and not in Megapixel. The question is confusing and I really don;t know what to pick, so I just picked the highest/default setting. but it seems to never get the ratios/area right.

 

The demo labels/xml combos seem to work again, but these have all been pre-arranged to the proper settings.