Deny downloading multimedia (pictures, videos, sounds) through a proxy?

Question

Network administration

It is necessary to solve the following problem, there is a machine on which a certain number of programs are running, access to the network through the ProxyCap application by using a proxy. How is it possible to filter traffic so that multimedia is not loaded. Is there an efficient way?
(Browser extensions are not suitable, it is necessary to completely limit the download of multimedia to all traffic, or alternatively, if it is possible to select certain programs for which there will be such a restriction, then this method is also suitable)

Answer 1

There are a lot of extra tags here.
ProxyCap is a typical "fighter for your and our shvaboda", it only refers to a proxy by name. Its main functionality is to shy away from the state, it is unlikely that it provides features that are typical for a normal corporate proxy.