Realnet have been in the process of adjusting imagery on websites and web applications with the help and guidance from Google's tools to optimise them for best display and loading speed.
This is a balancing act between producing imagery that is good enough quality for varying sized screens and different device types.
Realnet is trying to produce images that are high quality, but not too large to slow websites or web applications down for viewers or customers. We adhere as closely as possible to Google Pagespeed Insights keeping pages high quality but also sensible and usable. There are a number of main image file formats that are used, namely: Jpeg, PNGs, gifs and more recently SVGs.
Have a look at your website and see if the images or other page elements need optimising.
This short article covers it nicely.