When you are creating a slider it is possible to have a layer only appear on desktop, tablet or even on mobile. This could be useful if you would like to optimize the size of the layers, so your users will always see the important part of that. That could be also use for specify what they will see e.g. in a promotional ads, depending on which device they use.
How can I use this feature?
To use this feature is quite easy, click on the slider to edit, and then click on a selected layer. Then you will see 3 icons for each mode (desktop, tablet and mobile). By default all layers are visible on all devices, but if you click on an icon, then it will be hidden on the selected device. It is also easy to identify which layer is hidden on a screen size, because that icon is grey. If you click on that icon again, you will enable that.
Screen size icons
How can I check it the slider preview?
In the slider preview you can also check how the slider looks on different devices. Scroll up to see the Preview bar, and you will see the same device icons. If you click on one, then that screen size will be used for the preview.
Slider Preview Screen Size