How to properly cite (and write a paragraph) that a paper is based upon another paper but proposes different contribution?
I think using the data isn't an issue and you can just simply cite the paper. As far as anonymity goes, just citing and using that data doesn't disclose the anonymity. Unless there is a rule where an experiment in paper A can not be carry forwarded in another paper, you should be good to go.
To write it properly, refer to some other paper in your domain which does the same. In CS, there are multiple papers churning out solutions for the same data.
Re-using images is something I would suggest not to do, newer examples of potential edge cases in the previous paper would hold better. It generally is allowed unless mentioned explicitly.