If you're looking for some inspiration for making your own puzzle with this mechanism, I can think of two past examples right now (warning: spoilers for the mechanisms for these puzzles!):
- Foreign Box Office (from MIT Mystery Hunt 2020): This puzzle involves finding pairs of false friends (words which are spelled the same but have different meanings in different languages) in a given piece of text and connecting the ending periods of the sentences where each such pair is found. The resulting drawing is a pictorial representation of the solution to the puzzle.
- Shot in the heavens afar (from right here on PSE): This puzzle might seem like a typical riddle with an additional acrostic component, but if you find where the 's' characters are located and connect the dots, you'll reveal a nice visual surprise! This doesn't involve punctuation marks, but the basic idea is the same.
So it seems like this mechanism can be used to hide drawings of certain objects - what you do with those drawings is up to you.
Also, the main thing to remember whenever you're coming up with a mechanism for any puzzle is to always provide an indication of the mechanism being used in the puzzle itself:
- In the MIT Mystery Hunt puzzle, the first two sentences of the text contain the phrases "make connections" and "draw the line," which strongly hint at the period connecting mechanism.
- In the PSE riddle, the intended mechanism is less strongly implied, but the flavortext does contain the sentence "The answer is actually staring at you in the face... quite literally... can you find it?" and the puzzle is tagged visual and letters, which both point toward the letter connecting mechanism.
So, if you do end up using this mechanism, make sure you provide enough information to solvers so that they know that it's being used - otherwise the puzzle would wind up being very unfair!