How formal should figures in a thesis be? I am currently writing my masters thesis. I include in it a screenshot of a webpage, in which I want to point at some components and explain what each of them does. What I did so far is that I draw circles around the components and an arrow from the component to a one word text saying what it is, I intend to go into details under the image.

Is that sort of “labeling” formal enough for a thesis figure? Or is there another presentation that would be more appropriate?
Images in a thesis should be of the same quality as images in a peer-reviewed publication. Hand drawn circles and arrows are not formal enough. Circles and arrows drawn with programs like TeX, GIMP, Illustrator, or Powerpoint are formal enough.