The alt attribute for logos and buttons are done differently than the alt text used for other kinds of images. Google discusses the right way to do it.

One such example of this is when the Xbox logo button on your Xbox One or Xbox Series X/S controller starts flashing, and no matter what, you can't seem to get it to stop.

The logo button works from anywhere within the Sky interface, ... for example, 'skip five minutes' or 'restart' the show. And, what's more, if you ever lose the remote, ...

YOUR iPhone’s Apple logo can act as a clever “secret button”. The back button can perform loads of handy tasks – including taking screenshots. It’s called “Back Tap\b… ...