This piece of ancient Egyptian art dates from XI Dynasty and it was found in Thebes. In just a space of 70 cm x 60 cm (approx.) the Egyptian artist could include a number of typical scenes which dominated the corpus of funerary Egyptian art.
Although the whole composition does not have a narrative logic, the greater part of the activities can be identified: butchery, bakery, offerings…
At the left of the middle register there is an isolated scene, which was not too usual in ancient Egypt art: the dead lies on his beer and he is embraced by a smaller figure. According to the information from the British Museum's website: “The man on the bed is probably the deceased, and the figure on top of him might be one of a variety of goddesses, such as Isis, Nephthys and Nut, who embraced him. Whether there are any sexual connotations in this scene is uncertain.”
There is a very similar scene in the coffin of Henui from Guebelein and dating from the XIII Dynasty. The Egyptian artist chose to represent the dead being assisted by two women (the two mourners in the role of Isis and Nephtys) while a feminine figure lies over him for revitalizing the body.
One of the purposes of the mourning rite in Ancient Egypt was to give back to the dead the virility and it seems that the Egyptian art of the Middle Kingdom found the way of depicting this sexual symbol of the funerary thought.
In the stele of Sebekaa the Egyptian artist included in the funerary corpus the moment of the mourning rite. He could have chosen to represent that moment just with the image of the two mourners at both ends of the beer, but in this case, we do not why, he depicted a sexual moment. So, the sexual connotation would not be uncertain, but sure.