@vic18t
Try changing the padding to expand the active area for the button:
.sqs-lightbox-meta-trigger { padding-top: 15% !important; padding-left: 90% !important; }
Increase size and add a new color if you want the dot to stand out (replace "red" with your color code ex: #bcbcbc):
.sqs-lightbox-meta-trigger { padding-top: 15% !important; padding-left: 90% !important; color: red !important; font-size: 3em !important; }
Let me know if that works.