GM was planning a major restyling of its B and C bodies -- used by Oldsmobile, Buick and Cadillac -- for the 1954 model year. This new styling included what then was considered a futuristic feature, the panoramic or wraparound windshield. Such windshields had appeared on show cars such as the LeSabre and Buick XP-300 in 1951 and for 1953 they were grafted onto two production models in anticipation of the '54s. Those models were the top-of-the-lines Cadillac Eldorado and Oldsmobile Fiesta, both convertibles featuring a dropped, flowing door and shoulder line. Buick also was given an expensive convertible with the same flowing line. But unlike the Eldorado and Fiesta, the Buick Skylark had a conventional windshield.
The Skylark name was continued for 1954 as a convertible based on the new styling. A strong effort was made to give the Skylark a distinctive appearance, but the effort was flawed. In any case, the dramatic new 1954 standard convertibles were exciting enough and cost less, so the Skylark was not continued for 1955.
Compare this to the 1953 Buick Super convertible below. Differences include the cut-down door line, a slightly shorter windshield, a cleaner rear fender and a reshaped "Sweepspear" on the side.
This was the best comparison photo that I was able to find on the Internet.
For 1954 the Skylark featured larger, reshaped wheel openings and a distinctive rear end.
This is a Barrett-Jackson auction publicity photo showing the rear, where most of the changes were made. Compare to the photo below of a standard '54 Buick convertible. The trunk was both lowered and rounded-off, thereby reducing storage capacity. To prevent this area from looking too "soft," those odd chromed tail light assemblies were added.
This also is a Barrett-Jackson auction publicity photo from a similar point of view to the image above.