Final answer:
In trademark infringement cases, similarity is determined by the overall impression created on consumers, which includes a mix of visual, phonetic, and conceptual factors that could cause confusion.
Step-by-step explanation:
The "similarity" between two marks in a trademark infringement case is determined by the overall impression created on consumers. This includes but is not limited to visual resemblance, phonetic resemblance, conceptual similarity, and any other factors that could lead to confusion amongst the public.
The courts assess whether the overall impression of the marks in question could cause a "likelihood of confusion" about the source or sponsorship of the goods or services involved. In the case of Buc-ee’s versus Choke Canyon, the court found that the visual components, color schemes, and thematic elements of the logos were similar enough to cause consumer confusion, thus ruling in favor of Buc-ee’s.