What sort of subjective experience does this suggest?

From the New York Times.

[Experimenters] had cats step their forelegs over a three-inch barrier, then distracted the animal while the barrier was lowered. When the cat moved again, it raised its rear legs as if the barrier were still there. “That memory of that obstacle lasts for as long as that cat stands there,” [David A. McVea and Keir G. Pearson of the University of Alberta] said, though because of the difficulties of herding cats, the longest they were able to distract one was 10 minutes.

In that study, though, it was unclear if visual cues, or something else, resulted in the long-lasting memory. So in the new work the researchers repeated the experiment with a twist: they stopped the cat after it had seen the barrier but before it straddled it. When the cat moved on after more than a few seconds it did not raise its rear legs enough.

“The movement of the forelegs does something unusual,” Mr. McVea said. “It cements the memory of the obstacle.” They had similar results using a barrier that the cat could feel but not see, demonstrating that visual cues were not necessary to create the memory."

I don't understand the second experiment. Of the cat didn't step over the barrier with its forelegs but was allowed to resume after the barrier was retracted, why should it step over the barrier with its rear legs?

There are, of course, all sorts of ways for this behavior to occur. But the easiest one to imagine is that the cat has what we would call a short term memory, which we experience as something like a mental image, i.e., subjective experience.