Popup render in `container`

If the popup was rendered in the body or in the toolbar we get the expected result. If the popup was rendered to the button, the result is different. Was it so planned?
https://snippet.webix.com/f8cyrbl2

Hello,

Container is an HTML container where the component should be initialized
https://docs.webix.com/api__link__ui.view_container_config.html
You can try show(webix.$$('btn2').$view)
Sample: https://snippet.webix.com/hf70t1c9

That’s it. In this case, it is important to render the component to the selected DOM-node. What for “body” and “toolbar” works. If you render in a button, the popup is broken.