Privacy Browser Android

The answer to that question depends entirely on how the website determines when to send a desktop view. For example, a few websites use the width of your screen to determine if they should send a desktop view. Firefox has the ability to lie to the website about the width of the screen and does so in their Desktop Mode. Android's WebView does not provide that functionality (although that is a planned feature for Privacy WebView).

What is an example of a website where Firefox can display a desktop view and Privacy Browser cannot?

I think it is important to distinguish between two related ideas that are sometimes conflated.

1 - Some websites have two different versions of the website, one that they send to desktop browsers and another that they send to mobile browsers. When you make a request to the webserver, it analyzes the request and makes a determination as to which version of the website it will send in response. Based on whatever criteria the webserver uses to decide, you will receive different HTML, CSS, and JavaScript responses. This is known as adaptive web design:

https://en.wikipedia.org/wiki/Adaptive_web_design

Wikipedia is an example of a website that does this. In this case, the purpose of a desktop mode is to convince the webserver to send different HTML, CSS, and JavaScript files to the browser.

2 - Other websites send the same HTML, CSS, and JavaScript to all browsers. The are built using adaptive design, where the HTML, CSS, and JavaScript adjust the layout in a way where it makes sense on any screen size. This is known as responsive web design.

https://en.wikipedia.org/wiki/Responsive_web_design

trackerninja.codeberg.page is an example of this. In this case, the purpose of a desktop mode is to convince the HTML renderer to layout the HDML, CSS, and JavaScript files differently. It often does this by lying about the true width of the screen to make it layout more like the desktop.

As mentioned above, Android's WebView does not currently provide a way to lie about the width of the screen. But, it is a planned feature for Privacy WebView.

https://redmine.stoutner.com/issues/233

You can verify that trackerninja.codeberg.page is using responsive web design and that it lays out the same as it does in Firefox in "Desktop Mode" by viewing it in Privacy Browser on a device with a larger screen (see attached screenshot).