In this current age, this usually means an SPA that will first load the underlying page, then the entire application bundle, start up the JS, detect the route, load the data for the modal over another request, and finally display the modal. In the multiple seconds this is happening, nothing indicates that a modal will be opened. Sounds familiar?
Problem is, this is the standard, not a particularly poor implementation. I don't even know where to find an example that shows UI feedback before the modal is loaded.
In this current age, this usually means an SPA that will first load the underlying page, then the entire application bundle, start up the JS, detect the route, load the data for the modal over another request, and finally display the modal. In the multiple seconds this is happening, nothing indicates that a modal will be opened. Sounds familiar?