I collected all the messages that we sent to each other during 2019 and grouped them by season. The triangle of each participant in the correspondence in each season is "reflected" horizontally.

On the left side there are messages sent by me, on the right side — sent by my brother. The area of the triangle corresponds to the number of messages with certain type of content

For the text messages I applied two types of fill — black and striped — they change in a checkerboard pattern