[Fe X]λ6375 versus [O III]λ5007 luminosities for (a) ECLEs (Wang et al. 2012; b) variable ECLEs (Yang et al. 2013; c) AT2019aalc (this work); (d) the TDEs AT2019qiz (Short et al. 2023), AT2018dyk, AT2022fpx (Lin et al. 2025), AT2018bcb, AT2021qth and the TDE/QPE AT2022upj; (e) the repeating pTDEs AT2020vdq (Somalwar et al. 2025a) and ASASSN-14ko; (f) the BFFs AT2017bgt, AT2021loi (Makrygianni et al. 2023), F01004-2237; and (g) the BFF candidate AT2019avd (Malyali et al. 2021). A sample of different types of Seyfert galaxies (Gelbord et al. 2009) is plotted as well. The orange line represents a linear fit to the sample, and the orange shaded area represents the 95% prediction interval. The transient sources have clearly higher [Fe X]/[O III] luminosity ratios than the Seyfert sample.