I see no problem with that at all
If the landlord is selling, thats his right of course but most people buying would want steady tenants if it was for rental and if purchasing for them selves, you would normally get at least a month for looking around for another place so I also wouldnt worry about that.
I think there may well be a case to phone the realestate and mention your concern and offer to show someone else through or send a photo.
I honestly think that there is no problem at all from showing us your photo