You can set different logo sizes for primary and supporting sponsors. The uploaded file's shape and whitespace also affect how large a logo looks.
Set the event-wide logo sizes
Open the Theme Editor, switch to Advanced mode, and scroll to App Settings.
Primary sponsor size controls logos for sponsors marked Primary.
Supporting sponsor size controls logos for sponsors marked Supporting.
These settings apply where the event site presents sponsors according to prominence. Filtered or grouped Sponsor Grid blocks keep their existing layout and use the primary sponsor size.
Set the shape for an individual logo
Go to Content & Schedule > Sponsors, edit the sponsor, and open Media. Set Logo Shape to Square for a square logo, or leave Default (Wide) selected for a horizontal logo.
The shape helps HeySummit apply suitable padding so square logos do not look too small next to wide logos.
Check the logo file
Whitespace around the original image affects the displayed size. If a logo still looks too small, crop unnecessary whitespace from the file and upload it again.
Landscape and square logos usually display best. Portrait logos can be difficult to read in sponsor grids. For those, consider adding a wider image to Sidebar Promo Banner on the sponsor's Media tab.