If you are older and you are really close tho the person that passed on i think personally that you should be able to take a selfie i guess it all depends of if you are taking a picture with the dead person that is perfectly fine. But if you are taking a picture with the person that has passed on that seems a little rude.
It might indicate that one is feeling good about him/herself at a moment when people are expected to mourn and meditate about the loss. An individual has passed on, so why are you rejoicing while people are morning? Is that respect really? I don't think so, there should be some level of decorum at such an occasion.
Funerals deserve the most respect for the individuals that is deceased, and in no way should a selfie be taken at a funeral. Doing so disrespects the family members and those who need the privacy and comfort to think about their lossed ones. At a funeral, people should be very respectful and mindful of others and be a comfort to those. A selfie should be kept outside a funeral home.
It is highly inappropriate to take selfies at a funeral. It is disrespectful and you are there to honor the life of someone you have lost, not to show off how good you look in black. It's acceptable at most occasions, but this is one that I believe draws the line.