Orientation using regionprops and getting orientation at each pixel

I am trying to use regionprops to find the orientation of objects/pixels in an image. I will then use this data for further calculations later on. I am, however, having trouble understanding the output of regionprops.

I am giving it a 512x512 image, but I get our a vector of area that is 128x1 structure. I, however, am not sure how to say figure out the orientation at a specific pixel. Say I want to know the orientation at X:222, Y:111. I do not understand why it is a structure of 128 elements long?

?

    myImage = imread('testing.png');
    s = regionprops(myImage, 'Orientation'); 
    ori = [s.Orientation];
    componetsOfImage = ismember(myImage, ori);
    imshow(componetsOfImage)

And example image:

When I show the image of ismember, it works perfectly. But how is it working? The second argument is only 128 elements long? Yet there are 512x512 data points in the image?