Adobe Help says:
If the Multi‑Camera Monitor displays the same frame in large previews on both the left and right side, the current clip is either not a multi‑camera clip or a multi‑camera clip that is not enabled.
Did you create a new sequence and nest the source clips in it? (The multicam sequence is not the one with the source clips.)
Once you have the multicam sequence, did you enable it? (Clip -> Multicam -> Enable) Then you use the multicam monitor.
you have the sequence with the 2 clips synced. create a new sequence, call it target seq. drag the synced seq into the target seq. enable multi cam. then bring up multi cam monitor. you should see both clips on left and main monitor on right. (I see that your second clip start a little later in timeline then the first. so, in multi cam monitor you won't see the sec clip untile you scroll over to point where both clips appear.
Thank you so much for your help - all of you. Because of your help my problem's solved.
I'll definitely check out the tutorials, too.
You're welcome. Happy editing.