Before I became a birder I would not have noticed much difference between these two gulls. Now I can see all that distinguishes them as different species, including different leg and bill colors, size and shape, eye markings etc. However, gulls are still very tricky for me to identify. Side by side photos like this really help.
Marvelous for you to sight the two species together. I agree it is amazing the things you "see" when you become more interested and informed on a subject.
I am noticing things like this now. Which came first, your love of photography or birds? My love of photography led me to become a birder. It's so much easier to study the birds in photos than live so I began to notice the smaller differences.
This is terrific - like noticing the colored nails the other day. I am trying to learn to pay closer attention to those details. They really are standing at alert so straight here - beautiful shot.