Although Huck does not see it as comic, what does the reader find humorous about the titles of the dead girl's pictures?

The titles of the pictures are just meant to be irony. First of all the daughter obsessed with death is dead. The picture are dark, and they are all entitled with messages. Read them as if they're notes left behind rather than the titles of artwork. That should give you a better perspective. They really aren't funny.......

"There was some that they called crayons, which one of the daughters which was dead made her own self when she was only fifteen years old. They was different from any pictures I ever see before -- blacker, mostly, than is common. One was a woman in a slim black dress, belted small under the armpits, with bulges like a cabbage in the middle of the sleeves, and a large black scoop-shovel bonnet with a black veil, and white slim ankles crossed about with black tape, and very wee black slippers, like a chisel, and she was leaning pensive on a tombstone on her right elbow, under a weeping willow, and her other hand hanging down her side holding a white handkerchief and a reticule, and underneath the picture it said "Shall I Never See Thee More Alas."

Another one was a young lady with her hair all combed up straight to the top of her head, and knotted there in front of a comb like a chair-back, and she was crying into a handkerchief and had a dead bird laying on its back in her other hand with its heels up, and underneath the picture it said "I Shall Never Hear Thy Sweet Chirrup More Alas."

There was one where a young lady was at a window looking up at the moon, and tears running down her cheeks; and she had an open letter in one hand with black sealing wax showing on one edge of it, and she was mashing a locket with a chain to it against her mouth, and underneath the picture it said "And Art Thou Gone Yes Thou Art Gone Alas."

These was all nice pictures, I reckon, but I didn't somehow seem to take to them, because if ever I was down a little they always give me the fan-tods. Everybody was sorry she died, because she had laid out a lot more of these pictures to do, and a body could see by what she had done what they had lost. But I reckoned that with her disposition she was having a better time in the graveyard. She was at work on what they said was her greatest picture when she took sick, and every day and every night it was her prayer to be allowed to live till she got it done, but she never got the chance. It was a picture of a young woman in a long white gown, standing on the rail of a bridge all ready to jump off, with her hair all down her back, and looking up to the moon, with the tears running down her face, and she had two arms folded across her breast, and two arms stretched out in front, and two more reaching up towards the moon -- and the idea was to see which pair would look best, and then scratch out all the other arms; but, as I was saying, she died before she got her mind made up, and now they kept this picture over the head of the bed in her room, and every time her birthday come they hung flowers on it.

Other times it was hid with a little curtain. The young woman in the picture had a kind of a nice sweet face, but there was so many arms it made her look too spidery, seemed to me.

This young girl kept a scrap-book when she was alive, and used to paste obituaries and accidents and cases of patient suffering in it out of the Presbyterian Observer, and write poetry after them out of her own head. It was very good poetry. This is what she wrote about a boy by the name of Stephen Dowling Bots that fell down a well and was drownded"