Liechtenstein has an agreement with the Swiss for freedom of movement between the borders so there are no formal border controls if entering from Switzerland under the Schengen agreement, provided you have valid travel... More
Liechtenstein has an agreement with the Swiss for freedom of movement between the borders so there are no formal border controls if entering from Switzerland under the Schengen agreement, provided you have valid travel documents for Switzerland. However, due to recent problems with attempts by illegal immigrants to enter the country to claim assylum, the Liechtenstein government are undertaking more spot checks, particularly on buses entering it's borders. So as there is no formal passport control between Switzerland and Liechtenstein, to answer your question, yes it's more of a souvenir stamp.