How does Apple's mobile phone send messages in full screen?

Take apple x, ios 13 system as an example:

1, turn on the "information" function of the mobile phone;

2. Click the "Edit New Information" icon in the upper right corner;

3. Enter the love icon in the edit bar, and press and hold the Send key to open the "Send with Effect" interface;

4. Click the "Screen" option in the interface and select "Send with Sound Effect" to send a full screen of love.