Let's look a little closer at the stamp pictured in the lower right:
What is missing in the textbook image?
Why, it is the Hebrew part of the British Mandate stamp that says "Palestine (Eretz Yisroel)"!
Palestinian Arabs always accuse Israel of trying to erase Arab and Muslim culture, but as usual it is just projection for what they do, day in and day out, in trying to erase any vestiges of Jewish presence from the historic Land of Israel - from even as recently as 70 years ago.
Besides the outrageous airbrushing of history that this represents, more subtly, the textbook takes an item from the time of British rule and pretends that it somehow represents a historic nation of Palestine that never existed.
(In fact, other stamps in the same series depicted Jewish and Christian holy sites, as the British tried to be even-handed when they issued stamps.)
The preamble for the UNESCO constitution declares:
...[T]he States Parties to this Constitution, believing in full and equal opportunities for education for all, in the unrestricted pursuit of objective truth, and in the free exchange of ideas and knowledge, are agreed and determined to develop and to increase the means of communication between their peoples and to employ these means for the purposes of mutual understanding and a truer and more perfect knowledge of each other's lives.
This single example shows that Palestinian Arabs have zero interest in the noble original goals of UNESCO,and instead are interested in furthering their own selfish agenda at the expense of the truth, of other people and other cultures.
(photos from IMPACT-SE and miff.no, h/t JPost and Ian)