I'm not sure if you are saying this "tongue in cheek" but if not I think Edy has the correct usage on this, the Cambridge Dictionary definition is below but the example from it shows it more clearly in the use that Edy made of it:
Meaning of dissimilar in English
dissimilar
adjective
UK /ˌdɪsˈsɪm.ɪ.lər/ US /ˌdɪsˈsɪm.ə.lɚ/
different:
The new house is not dissimilar (= is similar) to our old one, except that it's slightly bigger.
Edy said "not dissimilar" which means =is similar as above, but which does not mean the same as. It appears to me he was saying they are different but have similarities.
