As a changing line this stroke arrives when a querent has been offered a shortcut that would make them look better than their position warrants. The carriage in the image stands for anything that supplies standing from outside: a title not yet earned, an introduction traded on somebody else's name, a purchase made to be seen. The counsel is to decline it and walk, and the line frames that refusal as the graceful act rather than the austere one.
There is a practical calculation inside the imagery as well. Display that outruns substance has to be maintained, and maintaining it consumes the effort that would otherwise go into acquiring the substance. A querent early in an undertaking, which this position usually indicates, has very little to spare for that. Going on foot is slower and it is also cheaper, and at this stage cheaper is what allows the going to continue.
Firm and correctly placed at the base of the lower trigram Li, the line has genuine strength and no altitude at all, which is the exact combination the counsel suits. Readings land here on the first job, the new practice, the early stage of a venture, the point at which someone is tempted to present themselves as further along than they are. The line is not asking for false modesty. It is saying that at the bottom of the hexagram the honest account of where one stands is already presentable.