1. Head tube should aligned with the fork. GPT-5.6 Luna is particularly terrible here.

2. Bikes are almost always depicted going rightwards so you can see the drivetrain. 4 failures in this.

3. Only ~7 of the 23 models achieved a diamond bicycle frame shape

4. Almost all the models have the bird directly over the crankset; as little as 4 or 5 have the birds sitting on a set-back bicycle seat.