The team at bat had runners on first and third. They attempted to pull a delayed double steal, but when the runner on first ran for second the catcher bobbled the ball and didn't throw it down to second. So now the offensive team has runners on second and third. On the next pitch the runner on second runs back to first ... so they can try the double steal again. LOL.
If this happened in the early 1920s, I would have guessed that the reverse steal would have been done by the Yankees to keep first base occupied so that the opposition had to pitch to Babe Ruth. (By the late 1920s, it would not have been attempted because most teams would be less inclined to intentionally walk Ruth because they would just be facing Lou Gehrig with another runner on base.)