The Deceased Praying Not in His Usual Place
Scholars have said that seeing a deceased person praying in a place other than their usual prayer spot during their life may indicate that they have received the reward for a good deed, as if they were performing it in life, or the reward for an endowment or charity. If the deceased was a ruler, their descendants might attain a similar position.
Per Ibn Sirin's Muntakhab al-Kalam fi Tafsir al-Ahlam
Note: These are traditional scholarly interpretations (ijtihad) drawn from a specific classical source — not a binding religious ruling, fortune-telling, or a prediction of the future.