A new tool bar of icons is displayed. There are 6 buttons. One for quoting, for translating, for getting Maths layout, for reactions (emojis and custom ones) and markdown. A last one to close the bar at the left.
https://storage.gra.cloud.ovh.net/v1/AUTH_91eb37814936490c95da7b85993cc2ff/tootfedilabapp/media_attachments/files/111/093/329/295/070/298/original/2139ed5f3fddcf43.png