I also really enjoy studying and reflecting on the covers of books. Most of those I choose these days don't have pictures, so the cover is the only real visual storytelling element. From it, I can usually glean something about the text, often including symbols and hints about what's to come. Love a good book cover!!
I always look at the covers of a book first, but if it includes pictures in the text, I usually look at them as I read (not before). However, I do use cover art as introductions to novels in my classes. I'll have students study the cover and discuss it amongst themselves. Then, we discuss what the implications of such art could be for the story. It's an exercise in prediction, which is an important skill for strong readers.
I definitely look at the pictures before beginning to read a book. I enjoy looking at the contents of the cover and analyzing the type, choice of colour, illustrations or graphics, photos, size and distribution of the design.
I do not think that adults and children learning differently, however. I do believe that the differences in how people learn are in the differentiated learning styles: visual, auditory,and kinesthetic.
I always look at the pictures before reading a book just like I always flip through the book and look at the table of contents to begin to wrap my brain about what is included before I actually begin to read. As I am reading, then, I can begin to fit details into the "bigger picture" I formed before reading. This is what good readers do.
I don't know that a child's reading preferences and dispositions change all that much over time. Certainly, we all grow and our interests expand with our own experiences. However, most of the same topics I found interesting when I was young are still topics I find interesting as an adult. Nothing has been "lost;" I've simply added a great more to my list.
I don't think adult reading preferences differ very greatly from those of a child.
Children and adults alike read for pleasure, read to learn (although children may not consciously realize this), read out of curiousity, read because they are made to read, read to connect to something outside themselves...
I think part of being successful in the world of education/knowledge as an adult is remembering what it was like to learn as a child. The most successful teachers are the ones who can impart knowledge in a way that is digestible, practical, and interesting. Children are uncorrupted by due dates, grades, salaries, deadlines, etc. However, in the adult-world, all of those things take care of themselves when we pursue knowledge with the same excitement and purity that we had when we were little.
The main difference in the adult approach to reading (and learning) and the child's approach, is that children do not have as many external factors weighing on their decisions to do ANYTHING, including selecting reading material.
I think that there is much to indicate that good readers, regardless of age, examine the pictures in a book prior to reading it. Naturally, as a reader matures, they become more attracted to a particular genre, style or author and this guides them more than the pictures might, but prior to beginning reading, if a book has pictures I think it is an active reading technique to examine them before reading. All good readers develop the habit of previewing and prereading so that the mind has some background that will allow it to properly envision the text being read. From the earliest of ages, teachers instruct children to preread as an activity that precedes actual reading. Examining pictures as part of this process is vital and something that I think one would see mature and developing readers alike experience.
I look at the colour and what's on the front cover. The main thing that appeals to me though is the title. When I see a good title, I just pick up the book and start reading the blurb. Most of the time, I end up putting the book back because the blurb doesn't appeal to me. I'm into the Blaze series of books, the characters seem so real and it's easy to get hooked!!