The word 'those' is properly followed by a description of what is being referred to. E.g. 'I like the look of those bananas'. (Note that the subject will be a plural).
The description may be left out, but in this case it would be 'understood' to be present.
'Them' is complete in itself. ' I like the look of them'. Adding a description after 'them' is considered incorrect usage. 'I like the look of them bananas!' is a no-no.