Additional Information (if any): I believe this portal was removed by mistake. In recent changes graffitis (especially like this one) are stil good POI Candidate.
I’d argue it’s not grafitti, but a mural, painted with explicit permission from the city - see Bailout folks / mural / Simpson (the source is in Polish, but deepL seems to convey its meaning pretty well)
I concur - another source (in English) Mazovia Warsaw Film Commission confirms both the location of this mural and that it was created with official permission during Street Art Doping Festival (Fundacja Do Dzieła)