Ratios work in both directions, so it is impossible to tell without clarification. Which is why you have to ask the seller in this case.
When teaching ratios (which I did for many years) my students would be marked down for not labeling. For example 3 apples:4 oranges and 4 oranges:3 apples. Both mean the same thing. So if they had written 3:4 or 4:3, it would be marked down as it is impossible to know what they were comparing. A sentence also worked: There are 4 oranges for every 3 apples. or The ratio of apples to oranges is 3:4.
While they are similar to fractions, they do differ because the order can change without changing the ration. With fractions, 3/4 does not equal 4/3.