I believe you’re seeing the alternate text displayed as " " or your image no longer works. The following formula works for me on the backend of salesforce (not a formula created in Skuid)
IMAGE(“https://www.komische-oper-berlin.de/en/favicon_16.png”;, “Alternate Text”, 16, 16)
Skuid shows the following .png image
I’m running Skuid Version 11.0.5
