Sometimes, your texts and images do not behave exactly how you'd like.
99% of the case, its because you havent checked or noticed the settings for the responsive settings in Revolution Slider.
First, make sure its enabled by going to Slider Settings > and enable "Custom Grid Size" buttons on the devices you want to have control on. See screenshot: http://d.pr/i/vJstcF
Once its enabled, edit your slide and you will new sets of device icons show up in your screen. See screenshot: http://d.pr/i/EI6JsE
Now check the video below for a full tutorial: