A web page is not allowed to look at your screen until you say so, each time. The questions below come from the browser. Vistralo cannot hide them, restyle them or answer them for you.
"Choose what to share"
This appears when you press Record. It lists your tabs, your windows and your screens. Nothing is captured until you pick one and confirm. If you close it without choosing, no error is shown and the form offers "Choose what to record" so you can try again.
The sharing bar
While a recording is live the browser shows its own notice that the tab, window or screen is being shared, usually with a button to stop. It stays for the whole recording. Pressing the browser's stop button ends the recording in the same way as pressing "Stop" in Vistralo.
The microphone
If "Record my voice" is on, the browser asks once whether this site may use your microphone. Your answer is remembered for the site. You can change it from the icon at the left of the address bar.
Sound from a tab
When you share a tab with "Record my voice" off, the browser's dialog may offer to share the tab's audio as well. With "Record my voice" on, tab audio is left out so that your voice is the only sound.
If you said no by accident
See Screen sharing was not allowed and Microphone not found.