This happened pretty quickly, but I captured several views on film. The first photo (above) shows the back of the prey, while the next photo (below) shows the prey flipped over, belly-side up.
The next image displays the prey from the side.
This tattler caught a small fish, probably a sculpin, although I'm not sure which species. I found one reference that talked about Wandering Tattlers catching freshwater sculpins at a lake in Alaska, but I don't know how often they eat marine sculpins. Examples of other prey listed for Wandering Tattlers include the following: aquatic insects (flies, crane flies, stoneflies, caddisflies, midges), polychaete worms, snails, amphipods, and small crabs.
Here's one more view, this time with the sculpin facing you. Seems like quite a bill-full for the tattler!