I've enjoyed working at Mosaic. The hours are flexible and the work is easy if you have the right personality for it (talkative, extroverted, upbeat), and the pay is fair (though some places pay you more for the same work, do your research).
A typical day at work includes setting up your asset (some lifting of around 30 lbs necessary), interacting with hundreds of people delivering key messaging about your brand, then tearing down and packing the truck.
The only complaints that I can venture are that the scheduling sucks, disregarding days which you've requested off, as well as sucky commutes. Activations can take place anywhere from Mississauga to the downtown core to Oshawa and you have to be there early in order to find the activation area. However, on the flip side, working somewhere new regularly means that you don't have the opportunity to get bored even if you're doing the same work.
In all, the coworkers make this job great, and working here has been overall a positive experience.