There can be no question of accuracy, because it's a purely fictional object. That said, the description of the shield in the Iliad does adapt various late artistic motifs that started to come in ca. 700 BC or a bit later, so it's possible to at least visualize bits of it. It has a lot in common with the shield in the Hesiodic poem called the Shield, which is probably getting on for a century later than the Iliad, but the two descriptions taken together strongly imply a tradition of elaborate shield descriptions, with many shared motifs.

But don't think of accuracy. Don't even think of ways that the shield description could feasibly be realized at the time - because it couldn't. Think instead of potential ways for audiences of the time to imagine the various scenes describes.

With that in mind, this schematic representation is an accurate rendering of what M. M. Willcock calls "a possible distribution of the figures" (A Companion to the Iliad, p. 210).

In terms of specifics, the depictions shown in the Wikipedia article would not be potential ways for 7th century audiences to imagine the shield, since the styles draw on artistic conventions from centuries later. This one is slightly less horrible, but still uses techniques from a good 200-300 years later than the Iliad. Out of the ones that turn up in a Google search, this one is probably the least silly, but it's still pretty silly because actual Greek art from ca. 700 BC looked more like this or this.