Yes — open the campaign and look under Audience. Tick Mobile alone and the timer, and the bar it sits in, stay off wider screens. It is decided by the width of the window rather than by guessing from the browser, so a narrow desktop window counts as narrow and the answer survives page caching.
The same panel limits a campaign to visitors who are signed in or out, and to particular roles once Signed in is ticked.
Still stuck? Ask the developers who wrote it. We aim to reply within one business day.
