This is not a bug. On nodes that have one input port and one output port (like Fetch Image) we show the input port label, but not the output port label, so one port of the node is labeled. On nodes where there is only one input port and multiple output ports, you don’t really need a label, since you can get the input type from the documentation if you don’t know it. On those nodes we omit the input port label to keep the node an uncluttered as possible.