Simple answer is, no
Selenium offers no way to display anything, period. It's a way to hook into other systems and so you would have to rely on those systems to display your "snack bar".
The only way to display something in a web browser would be to insert your own code to create the snack bar. But that would invalidate the test as you're not testing the site; you're testing the site and how it interacts with your code.
You could try tapping the language you're using to write the testing scripts to display something. For instance, it's very common when using Java to have System.out.println() to display information in the console. You could create a whole application that runs beside Selenium that puts up an OS-specific message box. But even then, there is a great chance of affecting the automation.
So there big question is, Why do you think you need to display something?
Generally, the point of automation is to run through a series of steps unattended. Where no one would be watching the process as it goes through the motions. So who is the intended viewer of this snack bar?
The only explanation is for debugging reasons. In which case adding this extra code is the worst thing you can do. You are already having an issue and you are trying to compound it by adding extra code that could skew the results. If you're trying to debug, then add external logging, such as the previously mentioned System.out.println() or an equivalent to your code and go from there. Something that would not effect the screen or the browser.
