When you are going into a playtest, you should have your expectations in the right place. You are going into a game that is not complete and looks nothing like a completed game. Prototypes can range from hand written on index cards to looking almost completed with game pieces from other games or cards that have been professionally printed. Whatever you end up play, chances are good, the final game will look nothing like what you are going to see.
There is a good chance the designer of the game has made some recent changes to the game and they have not yet explained the game to a group of people. The explanation may not be a clear as you would expect from a person who has played a published game 20-30 times. Designers are also hoping that the game will go over well during the initial explanation. There is a lot going on in a designers head when they are teaching a game. Knowing that going into a playtest will make the hiccups and possible confusion easier to understand.
None of that is to say that you can’t ask for clarification or prevent you from giving feedback about what you would like to see the components look like. While I don’t want to say “go in with low expectations” I think you should keep your expectations low and understand that this may be the first time the game has been tested. There may have been recent changes to the game the designer has not fully worked into their presentation. Designers have a lot going on in their head when they are presenting their game.
Expect to play a game that may or may not be good, but you will be able to tell the designer what could be changed to make the game more fun and you might even play a game that is a blast and fun was had by all.
If you have any comments or questions, leave a comment here or email Chris at firstname.lastname@example.org