Nope The extendable part has this little piece at the end that can hook onto something, as the object is pulled away, that part stays in place and extends the useful part of the object. On my version the extendable part locks automatically and you push the button to unlock it so it retracts. Other models have a manual locking mechanism instead.
I can't recognize it from the picture, but by your clues I'll have to guess that it is a measuring tape.
Yup We have a Winner! Now it's your turn to post a close up picture of something for everyone to guess.
That's what I thought it looked like after zooming in too, lol. But no, it isn't tile. Nope, not a screen either.