islandroofing is right, the roofer probably cut the shingles measuring from the wall, but didn’t account for the flashing, then when the flashing was installed the shingle was a tad to long and butted up next to the other shingle. Just go up there and apply some roofing cement to flatten it down (put one under the other if you need to). A tad sloppy but what matters most is it serves its purpose of being water proofed for years to come. After its flattened thats about all you can do. Noone really pays attention to roofs anyways.