How can I show less of more images based on the device type/size?

I have a responsive design for a website, so that it shows correctly either in desktop or mobile. My app is sort of a video gallery. (I'm using blaze, if that's relevant.)

However I would like to change the number of previews in desktop (about 9) and in mobile (probably 3), because a full screen in a desktop is different from a full screen in a mobile device.

I was thinking I could achieve this by filtering my collection, however how do I identify the client device?