What does ‘short but concise’ or ‘short yet concise’ mean?

If a text is short and concise at the same time, I would expect it to be referred to as ‘short and concise’, because concise implies short.

There are, however, quite a few occurrences of ‘short but concise’ and ‘short yet concise’ online. Is that kind of usage grammatical? What does it mean?

It sounds to me like ‘dark but black’, meaning ‘despite being dark it is black’, which does not make sense. (I’m not a native speaker.) Is there any reasoning behind ‘short yet concise’ that I’m missing?

P.S. Here is a random example (source).

Please provide a short yet concise brief overview of your project. e.g service required, web design, SEO, e-commerce etc, as well as your project objectives, goals, audience demographic, and potential budget.

Your expectation that a short text should necessarily be concise is not shared by most native English speakers. Hence the definition of concise in the Oxford Dictionary online:

Giving a lot of information clearly and in a few words; brief but comprehensive.

I have emphasized the ‘but’ in view of your remarks.

The default expectation is that the amount of information in a document/explanation/definition will be proportional to the number of words, and that if a text is shortened it will have proportionally less information. However any written text may contain material that is not essential to the meaning — examples, superfluous adjectives, personalization etc. Hence, the default expectation can be confounded if the abbreviated document maintains information content but removes inessential material.

Or, to put it more concisely than in the above paragraph:

Short does not necessarily mean concise