There is nothing wrong if a person sleeps or sits with the feet stretched out in the direction of the Kabah or the east with no intention of showing disrespect towards the Kabah.
If a person is sitting stretching his feet towards the direction of the Kabah with the specific intention of showing disrespect, then that is definitely considered a blasphemous act and a grave sin, for at all times we are ordered to respect the symbols of Allah. TheKabah, being the House of Allah, is worthy of utmost reverence.
The Prophet (peace and blessings be upon him) said, “O Allah! Enhance the honor, status and awe of this House in the minds of those who visit or go around it.” Allah says, “Whosoever respects the symbols of Allah, he does so only by virtue of the piety embedded in their hearts.”(Al-Hajj 22:32)
Having said this, however, I should further state: If a person does not have any such intention of showing disrespect to the Kabah, but he or she is simply stretching his or her feet in that direction merely for the sake of convenience, then there is no reason to consider it as being sinful.
There is nothing in the sources to indicate that it is haram in this case to do so. It is worth remembering the principle: Things are considered permissible unless forbidden.