Using the default theme “2013” of wordpress you can choose how many column (from 1 to 9) can have a gallery .
When you try to re-size the windows the images are automatically adapted for the new resolution.
On parabola this works when the column are from 1 to 3.
From 4 to 9 the images will not adapt the changing of resolution and smaller is the device, smaller will be the photo. On smaller device the photo are so tiny that you cannot see anything.
I Hope I explained well what is the problem 🙂