"What kind of a theme is this for a children's album?", one might be tempted to ask.
There are many things in Scripture spoken of as memorials, things which bring to remembrance. The rainbow is an example; God said that He would put it in the clouds to remind Himself of His promise to Noah and to all the earth. He would see, and remember His people and His promise. We would see as well, of course, and remember, but our remembering is not the important factor; God's is. There are many others; priestly garments, memorial portions of offerings, Passover, jealousy tests, and ultimately, the Lord's Supper. In almost every case, the offering is offered, the rite is performed, the garments are worn, and the Lord sees this, and remembers His faithful people for good.
How good of God to show us, in such a practical and regular way, that He will remember us for our good! Every week, we do what He says, in remembrance of Him, and every week He promises, in ways even a little child can understand, that He will feed and nourish us, that He will be our God and we will be His people. Grace upon grace, world without end, Amen.