After Allah (swt) has spoken about the manifestations of the cosmic system changes in the sky, His Al-Mighty speaks about the manifestations of the inversion of the order in the earth.
Allah (swt) has created the earth in a flat spherical shape to be adequate for the man livelihood:
وَالْأَرْضَ بَعْدَ ذَٰلِكَ دَحَاهَا
(And after that He spread the earth) (An-Naazi’aat: 30)
As for the hereafter, the appropriate situation for gathering is that the land be extended and wide for the gathered people.
It changes its shape as if it is stretched from its ends to expand after removal of the mountains and highlands out of its surface as Allah (swt) says:
وَتَكُونُ الْجِبَالُ كَالْعِهْنِ الْمَنفُوشِ
(And the mountains will be like wool, fluffed up) (AL-Qaari’a: 5)
Allah (swt) has explained this earthy phenomenon in another Surah:
فَيَذَرُهَا قَاعًا صَفْصَفًا %لَّا تَرَىٰ فِيهَا عِوَجًا وَلَا أَمْتًا
(And He will leave the earth a level plain % You will not see therein a depression or an elevation) (Taa-Haa: 107)