The element relevance has to do with the factor how relevant the landing page has to the visitor’s expectations.
In general, a visitor comes to the website via an advertisement, a search query, an email or something else related to promotion. In that promotion something is often depicted, colors and certain text expression are used.
The only thing the visitor expects when he clicks on an ad is a recognizable point.
If the ad is blue, but the landing page is orange, then there is a chance that this relevance is not there. The same goes for the message, the product, the title, text and more.
Make sure there is a connection between the subsequent steps that a customer / lead goes through.