There is a documentation issue at https://developer.atlassian.com/static/javadoc/applinks/3.6.1/reference/com/atlassian/applinks/core/rest/package-summary.html

The documentation for EntityResource states:

This service has two responsibilities:

1. Returning a list of entities local to this instance that are accessible to the logged in user.

It is missing the second number point below

This service has two responsibilities:

1. Returning a list of entities local to this instance that are accessible to the logged in user.
2. Proxying the above method from a corresponding EntityResource in a remote application instance (allowing local views to retrieve lists of remote entities)