Lazy loading based on device

[aghorilabs]

Is your feature request related to a problem? Please describe.
A lot of the themes I work on uses 2 different slider for mobile and desktop version (2 sets of images). Rebuilding them such that they use only 1 set of images is time-taking and is also has a lot of dependencies.

Describe the solution you'd like
If we have something like lazy-desk-src and lazy-mob-src where lazy-desk-src is used to lazy load only on desktop devices and mobile images will not load and vice-versa.