The Sole Survivor upon entering the Memory Den can persuade Irma to let them relive a memory. When she asks if a memory comes to mind, the Survivor can be upfront or elusive. Depending on speech choices, she may grant the Survivor a "free trial." If they go into the memory stasis pod, a screen with "Please Stand By" appears. The pod is very similar in appearance to the virtual reality stasis pods in Vault 112 of Fallout 3. The memory that is replayed to the Survivor is that of them waking briefly and seeing their spouse shot and son kidnapped. The memory plays like an out-of-body experience. When awoken, the Survivor is distressed, and Irma apologizes for putting them through that again.
The above experience is not available if the Sole Survivor first arrives to the Memory Den with Nick, so as to analyze a certain memory.
According to concept art, Irma was originally named Emma during development.
The following is based on unverified behind the scenes information and has not been confirmed by canon sources.
Irma shares a name with the famous burlesque performer Mary Goodneighbor, who used the stage name "Irma the Body" and performed in Scollay Square in the 1940's and 50's. It is possible that her name was also borrowed for the town in which the Memory Den is located.
End of information based on unverified behind the scenes information.