Line Thickness and Spacing Indicating Density Portals

In symbolism, watch for density change when a flow passes through a portal, shown with a difference in line thickness and spacing. Smaller, thinner is higher density. Flow direction works in either direction on these examples.

Image A, apparently the portal is the small loop at the top. It's kindof a loop-back. Two circles tend to be at the bottom of a layout. https://ca.pinterest.com/stevenbhalls/tuball/ Image B, I can't even guess how to name that location, somewhere at shoulder height. Image C and D use the hand-symbol as a portal.