on christmas day, Mr. shimerda comes to thank them for the presents. what does he he do to acknowledge the christmas celebration?

In late afternoon Mr. Shimerda comes over to thank them for all the gifts they gave his family. After escaping from the dreary dugout, he welcomes the Burden's home as an oasis of peace and order. He rests there and is completely content.

When Jim lights the Christmas tree, Mr. Shimerda kneels in prayer in front of it to acknowledge the celebration.