In simple words
A transit is where a planet is in the sky now, compared with your birth chart. Here, today's Mercury makes a opposition (180°) to the spot where your Sun was when you were born.
It is a time of pressure that pushes you to grow, and it lasts a day or two (longer when it is retrograde). Your Today page tells you when it is happening for you.
Love
A disagreement can teach you something. Stay curious.
Let someone finish their point before you answer.
Seek understanding, not agreement.
Work
Negotiations need patience.
Feedback from others may be blunt but useful.
Review rather than rush.
Mood
Mentally stimulated, maybe a little defensive.
Step back before reacting.
Quiet time helps you sort your thoughts.
About the opposition
An opposition places two planets across the sky from each other. Each one pulls toward its own side of life. Oppositions are often felt through relationships, as if another person plays one side. The work is balance: holding both needs instead of swinging between them.