Slate displays SImage as white box

My SImage is incorrectly displaying a white box.

This is what I wrote based on some examples:

SNew(SImage).Image(new FSlateImageBrush(FName(*FString("/Game/MyStuff/MyLogo")), FVector2D(250, 58)))

MyLogo is a UTexture2D asset. What should I be doing here?

Your texture is probably not loaded.
Try making a TAssetPtr<> to it then on module startup call *.Get()