On this page of my website, the mobile design looks different on different devices. On my phone, it looks as it should with the photo stacking on top of the text. However, on my coworkers phone, it doesn't stack...the text stays to the right of the image. Since we have a pattern in the background, this makes it impossible to read the text when it does that. Why is it different on different phones? How am I able to check my designs across all devices so this doesn't happen and we can make sure all of our customers are seeing it the correct way?