It's not an "Egyptian" pyramid; there is no link to anceint Egypt. Note that in Roman numerals it says MDCCLXXVI (1776) at the bottom of the pyramid.
The pyramid is lighted on one side and dark on the other to represent the sun rising on the new nation. It is uncapped because the nation was not yet finsihed". The all seeing eye is an ancient symbol for divinity; as that is part of teh seal of the United States, it was designed to represent that with God's help, this undertaking could be successful.
The star of David is 13 stars, representing the original 13 colonies, but do you know why it is in that formation?