I saw a similar joke photo - and found it in poor taste, but was not offended by it, and I am a practising Catholic.
After all, it is never going to happen. Trump is not a Catholic, which rules him out. Strictly speaking any Catholic male can be chosen - a pope does not have to be a cardinal, but traditionally popes were cardinals prior to their elevation to the Throne of St. Peter. They DO need to be pious, sound theologians and good at politics and diplomancy and have a reasonable knowledge of their own limitations. Concern for the poor, the homeless and the disadvantaged generally speaking, and concern for the environment are probably in the job description too.
Do any of these requirements bring Trump to the forefront of your minds?
No, I thought not.
Whoever thought up that joke, was surely not intending to insult Catholics, or the Catholic Church, but make the statement that he or she does not believe there are any bounds to Trump's self-conceit, or delusional belief in his abiltily to do any job on earth better than whoever is actually doing it right now.
There is also a joke going the rounds, that we have arrived at the Day of Judgement, and Trump is standing before the Almighty asking, "Why are you sitting in my seat?"
Blasphemous or funny? Take your choice.