I am a serious journal junkie, and have been for some time. As an undergraduate I discovered where the new issues of each key journal (Cell, Science, Nature, PNAS) could be first found. In grad school, several of us had a healthy competition to first pluck the new issue from our advisor's mailbox -- and the number of key journals kept going up. Eventually, of course, all the journals went on-line and it became a new ritual of hitting the preprint sites at the appropriate time -- for example, just after 12 noon on Thursdays for the Cell journals. A good chunk of my week is organized around the rituals.
Most pre-print sites, indeed most on-line tables-of-contents, are barebones text affairs. That's fine and dandy with me -- quick & easy to skim. But, I do appreciate a few that have gone colorful. Some now feature a key figure from each article, or perhaps a figure collage specifically created for display (much like a cover image, but one for each paper).
Journal of Proteome Research is at the forefront of this trend. Of course, since it is a pre-print site the particular images will change over time. As I write this, I can see a schematic human fetus in utero, flow charts, Venn diagrams, spectra, a dartboard (!), bananas, 1D & 2D gels, a grossly overdone pie chart, and much more.
Nature Chemical Biology is the other journal I am aware of with this practice. The current view isn't quite such a riot, because NCB doesn't have the large set of pre-prints that JPR has, but both a fly and a worm are gracing the page.
The graphical views do provide another hint of what might be in the paper beyond the title. In particular, they give some feel for what the tone of the paper might be (that dartboard must indicate a bit of humor!). They certainly add some color to the day.