We have been using this beautiful theme and there’s the only drawback of it is that feature images get pixelated at below 400×400 dimensions. All images of our website covering the whole screen as you can see on http://www.rtiwala.com/gauri-lankesh URL. Therefore, when suggested by Developer we tried with small dimension images and it’s getting pixelated and disappointing our readers.
Thank you so much for using our theme. In case of a featured image, did you check the options for featured image size on customizer?
1. Go to Appearance => Customize => Layout/Design Option => Default Blog/Archive Layout => Image Layout( Size ) Options and choose Image size to display
2. For single post Go to Appearance => Customize => Single Post Options => Image Layout ( Size ) Options and choose Image size to display.
Maybe that is helpful options for you. Kindly check the settings on customizer for single post options and try changing the image size.