* I came across a beautiful old photograph while cleaning the attic. (Meaning: I found it by chance)
* She comes across as very confident in interviews. (Meaning: She gives that impression)
* The detective came across a crucial clue hidden in plain sight. (Meaning: Found unexpectedly)
* He came across a group of friends playing frisbee in the park. (Meaning: Encountered by chance)
* The new CEO came across as arrogant and unapproachable. (Meaning: Gave that impression)
Let me know if you'd like more examples!